Welcome to the Carbide Processors Blog
How to Braze- Part 3
Posted on Thursday, May 17th, 2012 at 2:05 pm.
Welcome to our series on how to braze! We have put together a tutorial on how to braze and broken it up into 4 parts. We will be adding a new post every few days so be sure to check in and visit us often so you can take advantage of this valuable information. In parts 1 and 2 of this series we discussed saw plate and how to prepare the saw plate for brazing, and Flux and how flux affects brazing.
When brazing carbide tips you will need:
- Braze Alloy or silver solder
- Brazing Flux
- Carbide tips
- Steel saw plate
- Also, you will need a tool to heat the braze alloy
- And you will also need a tool to help guide the carbide tip onto the saw plate.
*For successful brazing the quality of the materials used is very important and can have a significant effect on reducing the amount of tip loss and breakage you experience. We proudly sell what we believe to be some of the best brazing flux, Braze alloy, and Carbide Tips in the industry.
Part 3: carbide saw tip and preventing tip loss and breakage
The Carbide Saw Tip:
It is essential that the carbide tip be tested for wettability. The simplest way to do this is to put a very tiny piece of braze alloy wire in the middle of the carbide tip with flux. Then heat the tip and see how far the braze alloy flows. If the braze alloy balls up there is something wrong with the tip. If the braze alloy flows out into a wide, flat puddle then the tip wets well. We sell Carbide tips and have a special treatment that increases wettability.
Heating
Theoretical and Actual Braze melting points
Steel saw plate heats up much faster than carbide tips. In tests it looks like it is about a ratio of 3:1 to 5:1. If you heat the steel saw plate and the carbide tip equally the steel will get much hotter, much faster than the carbide tip.
Whether you are using induction brazing or torch brazing you should apply your heat to and then through the carbide saw tip. Ideally the carbide saw tip will come up to temperature which will heat the braze alloy which will then heat the adjacent steel to a depth of no more than 0.200”. You can tell how much steel got hot by how far the braze alloy flows onto it. The outer limit of the flow should be no more than 0.200” from the carbide tip and 0.100” is better.
Tip Loss and Tip Breakage
This concerns just the carbide tip. Failure of the steel shoulder is addressed in Part 1 of our series.
Tip loss occurs when the braze alloy does not stick to the steel or to the carbide. If the laser cut saw plate is not gummed (ground) back enough the braze alloy may not adhere fully. The tip will come off. On the back of the carbide tip will be a series of horizontal lines stretching from side to side of the saw tip. These lines are marks left by the notches from the laser cutting. Laser cutting does not really cut. Instead it melts a series of connected holes. This is what creates the lines.
If the carbide tip is not treated properly for wetting and brazing the tip will come off and leave the braze alloy in the notch. Often there will be a thin gray film on top of the braze alloy in the notch. You can scratch this film with almost anything sharp and expose the yellow braze alloy underneath it. This is caused by the surface treatment on the carbide coming off. So the braze alloy stuck to the surface treatment but the surface treatment did not stick to the carbide.
MEGA Flux- New and improved brazing flux
Posted on Wednesday, May 16th, 2012 at 12:17 pm.
What is flux and why use flux:
Flux is used for aiding in the brazing process. One of the main things that can cause a weak joint in brazing is impurities like particles, oils, dirt, or oxidation at the joint. Even if you clean the joint and remove any oils or dirt, the high tempatures required for brazing will cause the work piece and the silver solder to oxidize. Flux helps prevent oxidation during the brazing process. Many fluxes also have cleaning properties. You can read more about how flux is used for brazing in our “How to Braze” article.
The better the flux is the better your brazing reluts will be. Better flux typically has smaller particles in it as it has been filtered and processed more than standard black flux. It also has better cleaning properties.
We have been testing different fluxes since 1981 and Our new MEGA Flux is the best flux we have ever seen for brazing tungsten carbide. This flux cleans about 78% better than any other flux. This was a surface area test. We tested equal amounts by weight of Wolverine Black Flux, Carbide Processors Purified Flux and Carbide Processors Mega Flux. The Mega Flux cleaned 78% more area than either of the other fluxes.
With our New MEGA Flux you Will Get:
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78% Better Cleaning
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Much Better Bonding
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Reduced Tip Loss on Saws
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Reduced Breakage on all Tools
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Easier Clean up
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Easier Mixing
This Truly Is a Huge Improvement
We ran some production tests to see just how much better the MEGA Flux really was.
1. The first thing we noticed was that the flux had not separated as black flux does.
2. The next thing we noticed was how incredibly creamy, smooth the flux was.
3. We like to cut our flux with a little water for dispensing and the Mega Flux mixed beautifully. (You can also remix with water if it dries out.)
4. We tried the Mega Flux in a pretinning operation and the operator noticed that the Mega Flux did clean better.
5. The most important thing was that the braze alloy flow on the carbide saw tips was beautiful. There was an even flow to all four corners with no runover on the sides or the front of the carbide saw tips.
200 X pictures of the three brazing fluxes
Below are pictures of the three brazing fluxes magnified 200 times. The mega flux definitely has much smaller grains and there is a much greater consistency and homogeneity in the overall composition than with black flux or the purified flux.
How to braze- part 2
Posted on Tuesday, May 15th, 2012 at 2:15 pm.
Welcome to our series on how to braze! We have put together a tutorial on how to braze and broken it up into 4 parts. We will be adding a new post every few days so be sure to check in and visit us often so you can take advantage of this valuable information. In part 1 of this series we discussed saw plate and how to prepare the saw plate for brazing. In part 2 of this series we will be discussing how Brazing flux affects the brazing process.
When brazing carbide tips you will need:
- Braze Alloy or silver solder
- Brazing Flux
- Carbide tips
- Steel saw plate
- Also, you will need a tool to heat the braze alloy
- And you will also need a tool to help guide the carbide tip onto the saw plate.
*For successful brazing the quality of the materials used is very important and can have a significant effect on reducing the amount of tip loss and breakage you experience. We proudly sell what we believe to be some of the best brazing flux, Braze alloy, and Carbide Tips in the industry.
Part 2- Brazing Flux
Choosing a good brazing flux:
There are three types of brazing flux: White Flux, Black Flux And Purified Black Flux.
White Flux is potassium salts of boron and fluorine. It has some cleaning effect to remove oils and greases. It has some ability to remove existing oxides. Do not count on either one of those. Start with a clean saw plate that is oxide free. Flux, any flux, is designed to keep oxygen away from the braze alloy so that the braze alloy melts and flows instead of burning up.
Black Flux is white flux with extra boron added. Black flux is clearly superior to white flux for brazing carbide saw tips to saws. The simple switch from white flux to black flux can prevent or entirely eliminate tip loss and breakage.
Purified Black Flux is exactly what the name says. It is black flux that has gone through a separate, final, cleaning, filtering process. Ordinary black flux has some impurities and inert elements in it to keep the cost down. This is just fine if it is used entirely outside of the braze joint. In the case of brazing carbide saw tips to saw blades you also have flux between the braze alloy and the steel. If you are using ordinary black flux you will have these inert elements trapped in the joint. Purified black flux will create a more even braze joint that is typically 20 to 30% stronger than a braze joint created with ordinary black flux.
Flux -Applying Flux
The notches and both sides of the shoulders should have a layer of flux painted on them. It is very important that you get the whole shoulder of the saw plate as the flux helps protect the shoulder from the heat to a certain extent. The main purpose of the flux is to prevent the alloys in the steel from oxidizing. Many saw plates have nickel and chromium in the steel. If flux is not applied to the saw plate these alloying elements can be turned into nickel oxides and chromium oxides or chromium carbides and thus affect the strength of the steel. If you see color on your saw plate after brazing then you need to flux to prevent that coloration.
How to Braze- part 1
Posted on Monday, May 14th, 2012 at 12:07 pm.
How to braze- A 4-part series on how to braze carbide tips
Welcome to our series on how to braze! We have put together a tutorial on how to braze and broken it up into 4 parts. We will be adding a new post every few days so be sure to check in and visit us often so you can take advantage of this valuable information. In part 1 of this series we will be discussing saw plate and how to prepare the saw plate for brazing.
When brazing carbide tips you will need:
- Braze Alloy or silver solder
- Brazing Flux
- Carbide tips
- Saw plate
- Also, you will need a tool to heat the braze alloy
- And you will also need a tool to help guide the carbide tip onto the saw plate.
*For successful brazing the quality of the materials used is very important and can have a significant effect on reducing the amount of tip loss and breakage you experience. We proudly sell what we believe to be some of the best brazing flux, Braze alloy, and Carbide Tips in the industry.
Part 1: Choosing a saw plate:
A steel saw plate is laser cut. The laser cutting causes a heat affected and burnt and oxidized edge on the saw plate. This edge must be ground back to clean steel. Probably the safest figure to use is 0.010”. If you do not grind the edge on the saw plate back, the tips may still stick to the burnt steel but it will be a very weak bond.
Steel saw plate typically comes with some sort of a protectant to prevent rust. This must be removed from the saw tip seat as well as the adjoining shoulders. The best way to do this is with some sort of a caustic solution (sodium hydroxide, NaOH). A strong caustic solution breaks the oils and greases done into soaps which are easily removed. A solvent will dilute the oils and greases but will not remove them completely. Either cleaning method can work successfully but the caustic method is surer and more complete. For more tips you can read our blog on cleaning steel.
See our videos below on preparing steel plate for brazing
How to Prepare Saw Plate for Brazing
Broken and Ripped Shoulders
Broken and ripped shoulders are two separate things.
Broken (Snapped) Shoulders
During brazing it is possible to get the steel saw plate so hot that a change in structure takes place. This change in structure can cause a change of hardness of as much as 20 points Rockwell C. This makes the saw plate very hard and very brittle. If the saw plate is not correctly tempered back to the correct Rockwell and the correct toughness then it can snap during use. This is typically a very clean break.
I have seen instances, with an improperly maintained automatic brazer, where the heat affected zone continued into the saw plate as much as an inch below the bottom of the gullets. In this case a customer returned the saw blade that had a whole section missing. A section of five tips, gullets and all, had come off as a single piece to a depth of about an inch below the bottom of the gullets.
Ripped Shoulders
Ripped shoulders are different than snapped or broken shoulders. With ripped shoulders the steel is tempered correctly but the saw tip gets hit so hard that it actually pulls the steel apart. These are typically not clean breaks. They will often leave deformed steel.
Watch our video on:
Saw Steel Embrittlement
What router bit to use for cutting granite or marble?
Posted on Thursday, May 10th, 2012 at 3:45 pm.
When using a router bit for for cutting marble or granite then it is important to choose the right type of router bit.
Woodworking router bits are designed specifically to cut wood. They will burn up pretty rapidly if used for stone cutting. There are over 5,000 carbide grades available and probably about that many different ways to make a router bit.
The different types of router bits are designed for cutting specific types of material. Woodworking router bits are designed to work in a relatively soft material, at least compared to granite or marble, and are designed to cut fibers cleanly.
When choosing a router bit for stone cutting it is important to not only choose a router bit that can make cuts in a very hard stone material, but that is also designed to throw the dust out of the cut. When you make cuts in materials such as marble or stone, then there is a lot of stone dust created. If this is not thrown out of the cut, then you will be cutting through the fine sand made from the initial cuts as well as the very hard stone material.
When you are cutting wood with a wood router bit then you want to choose a router bit designed to sever the wood fibers cleanly so that it makes smooth cuts in the wood. When cutting marble or granite material, having smooth cuts is less important and you do not need a router bit with a very sharp edge. Instead, you would want to use a router bit with a very strong edge to increase your tool life.
If you are going to be cutting marble or granite, I would recommend using an advanced carbide grade like our cermet grade of carbide or look toward using diamond cutting tools like a diamond tipped router bit. You can find advanced carbide grade tools or cermet carbide tools on our website, or can call us for a quote. We offer custom tools built and designed by some of the finest cutting tool engineers in the industry.
How to replace Stump Grinder Teeth
Posted on Wednesday, May 9th, 2012 at 1:14 pm.
Step by step guide to replacing teeth on a Stump Grinder
What you need to replace Stump Grinder Teeth:
- A torch or other method of heating that will reach about 1500°F
- Black flux – must be a brazing flux, not a solder flux
- New, pretinned stump grinder teeth (a tip with braze alloy already on it)
- A pokey stick such as an old file. A ceramic rod is better but harder to find.
1. Removing the old Stump grinder teeth
You heat the old stump grinder tooth up with a torch and then you flick or push the old tooth off. The old stump grinder tooth will typically not fall off on its own. Folks, to retip sawblades use kind of a sharp, flicking motion to knock the old tooth off.
2. Preparing for new stump grinder teeth
If you are replacing stump grinder teeth all you need to do is put the new tooth, braze alloy side down, in the same place the old tooth was. The new braze alloy will mix with the old braze alloy just fine.
If you are putting grinder teeth on your stump grinder for the first time then you need to make sure that your steel is free of scale or rust as well as free of oils or greases. Just wiping the steel clean may or may not work. Using a strong caustic cleaner and a thorough rinse is a much better way to clean steel for brazing.
3. Using the brazing Flux
You need a brazing flux, not a soldering flux. Using the wrong flux is the number one problem with replacing stump cutter teeth. Brazing occurs over 800° F and soldering occurs below 800° F. If you try and use a solder flux it will get all burned up before the braze alloy even starts to melt.
Flux serves as a cleaner and it prevents oxygen from getting into the braze area. If oxygen gets to the braze alloy then the braze alloy will burn up. If you have flux in the joint area than the braze alloy will melt and join successfully.
Just paint a little brazing flux into the area where you will be putting the new stump grinder tooth. Use the thinnest layer that you can get while still covering up the old braze alloy. If you use way too much the new tooth will tend to float away. If you don’t use enough then the flux will get burned up.
4. Placing the new stump grinder tooth
Put the new stump grinder tooth into the notch so that the gold, braze alloy side is against the brazing flux.
5. Heating the stump grinder tooth
Heat the tooth through the carbide. Steel will expand about two or three times as much as the carbide so heating through the carbide helps even this out. If you get the steel above 1500° F the steel will get brittle so you really want to heat through the carbide.
As you heat, three things will happen:
1. The water will boil out of the brazing flux
2. A little bit later the brazing flux will turn to liquid and spread out
3. Finally the braze alloy will melt
This is why you need the pokey stick or file
6. Using the pokey stick
When the water boils out, the flux turns liquid and when the braze alloy turns liquid the part can float and shift a little. Use the pokey stick to gently nudge the part back where you want it. Do not push down on the part with the pokey stick or anything else
7. Braze Joint Thickness
A thin layer of braze alloy in the joint will give you greater tensile strength. A thick layer of braze alloy in the braze joint will give you more impact protection and cushioning from shock. Our pretinned tips have a very carefully calculated amount of braze alloy on them to give you the best combination of braze joint strength and impact protection. Do not push down on the tip. You will push all the braze alloy out which wastes money and makes a much weaker braze joint.
8. Heat the stump grinder tooth to about 1400 F
This is sort of a dark cherry color. If you see any yellow or orange you have got the tip too hot. The pictures here are pretty good but they were taken in a dim light area. If you are brazing under bright light the colors will look different.
9. When you are done
Once you have the tooth heated up properly and nudged into the place you want it then gently pull your torch away while you hold the tip in place. Do not push down on the tip, just hold it in place.
Let the stump grinder tooth cool completely to room temperature by itself.
Do not use water to cool it.
Do not attempt to test the tooth or to use the tool before the stump grinder tooth has cooled to room temperature.
Worlds Best Saw Blades
Posted on Thursday, April 26th, 2012 at 9:36 am.
How to Build the Worlds Best Saw Blades
Worlds Best Saw Blade from Carbide Processors
As you might suspect, building the worlds best saw blades means using the finest materials, the finest equipment and the finest people.
It also involves a huge attention to details.
Here is one of the secrets we use to build the Worlds Best Saw Blades. Ordinarily we don’t give away secrets like this but I think this one does such a beautiful job of explaining the tremendous care we take that I am willing to share it.
After the Cermet 2 (a blend of tungsten carbide and advanced materials) saw tips are brazed on the saw they have to be ground to make sharp. This is somewhat harder than it sounds because the carbide is extremely wear resistant and tends to ‘push back’ against the grinding wheel. The steel saw body needs to be stiff so it cuts straight but it also has to have a certain amount of give to make it tough enough.
Ordinarily the teeth are ground from the top down. The CNC grinder is set to compensate for the carbide push back and for the give in the steel. This works well until you come to an expansion slot in the saw blade. (Expansion slots are the slits in the rim of the saw blade that compensate for the fact that the outside of the saw blade grows more than the inside as a saw blade turns.)
The teeth on either side of the expansion slot set on steel shoulders that give a little more than the steel shoulders under the other teeth because they sit on either side of the slot.
One way to compensate for this is to grind the saw tips on either side of the slot up instead of down. Depending on your grinder, the kind of wheel and the situation on the exact saw blade you are grinding you may also want to reverse the direction of the wheel as you grind these two tips. In some cases you will even grind the tips on either side of the expansion slot differently because of the difference in the amount of steel supporting the tip in that particular location.
One way to tell a really top quality saw blade from an average saw blade is to measure the side clearance of the tips on either side of the expansion slot.
It is not unusual to see these two tips sticking out on the side of the saw by as much as 0.0005” to 0.001” more than the rest of the tips.
Worlds Best Saw Blades
www.carbideprocessors.com
800 346-8274
sales@carbideprocessors.com
World’s Best Saw Blades
Posted on Tuesday, April 24th, 2012 at 11:32 am.
Are Our Saw Blades Really the Best
Worlds Best Saw Bade - Custom made blades form Carbide Processors
The truth of the matter is that there are a lot of people making good saw blades anymore. Part of that is due to people such as you. If someone does produce poor quality, it is exposed on the Internet.
Another factor is a more rigorous definition of what good quality means. You used to see saw blades on store shelves that would have runout of 0.008” or 0.010”. This is rare anymore. Now a retail blade should have a total runout of no more than 0.004” and many are down around 0.002”.
The blades Mr. Snook makes for us typically have a runout well under 0.001 inches but this is a pretty small difference for a lot of users.
Mr. Snook uses our advanced materials saw tips which cut cleaner and longer with less energy but, again, this is not a benefit that most users will see or appreciate.
Fortunately Mr. Snook and I are doing well in the industrial market. This is an area where wood cut is measured in miles instead of feet.
There really isn’t anything to replace steel in sawblades. You can alloy steel with nickel, chrome, vanadium and similar to make better saw plate. Warren Bird of California Knife and Saw make stainless steel saw plate that is considerably superior to ordinary saw plate but which is much more expensive.
One of the big problems with building better saws is that almost no one runs the saw it until it is used up. Weyerhaeuser once retipped one of their mill saws 50 times as an experiment. This doesn’t happen in real life. Much more commonly, in real life, the saw gets damaged or the steel loses its ability to hold tension.
Another consideration with saw steel is the cost of getting alloy steel that is homogenous enough and flat enough for saw plate. They don’t make any steel like that on the North American continent so it all has to be imported.
It is extremely difficult to try new steels on any sort of our production basis because the minimum order is 20 tons. So a significant test of a new steel means ordering 40,000 pounds. Plus it has to be shipped in sheets instead of rolled which adds to the cost.
As far as your Freud blades go, I’ve always been very impressed by their R&D department. It is pretty exciting to get a call from the head of Freud R&D saying he wants to buy one of my new sawblades. They are very competitive and do stay on top of the advances in the market.
Mr. Snook and I do well because we’re very small and we can afford to address a much smaller market than Freud can. So I invent saw tips that are little more expensive than carbide tips. Both Mr. Snooks are very, very good in every saw blade that leaves or shop has been individually made by a true master of the art. This is not something a major manufacture, such as Freud, can do so we have our own little niche and we are pretty happy there.
Worlds Best, Custom Built, Saw Blades
Tenryu Saw blades
Popular Tools Saw Blades
www.carbideprocessors.com
800 346-8274
Thin Kerf Saw Blades and Loss of Stiffness
Posted on Monday, April 23rd, 2012 at 10:27 am.
Thin Kerf Saw Blades
Thin Kerf Saw Blade Damaged
I got curious about how much easier it was to damage a thin kerf saw blades than a regular kerf saw blade.
I worked on it most of the day and finally found the answer on Dr. Bruce Lehmann’s website. http://www.thinkerf.com/
As saw plate gets thinner the stiffness of the saw blade falls off by the cube of the difference. If we take a saw blade that is 20% thinner than it has 80% of the original thickness. To calculate the difference in strength you take the 80% and multiply it by itself three times. Thus .8 x.8 x .8 = .512 or 51.2%.
Roughly a 20% reduction in saw plate thickness means about a 50% reduction in stiffness.
We sell many great thin kerf saw blades. Our Tenryu, Popular Tools and World’s Best are all specifically engineered for performance and safety.
We sell Great Tools
www.carbideprocessors.com
800 346-8274
sales@carbideprocessors.com
Overpressuring Braze Joints
Posted on Friday, April 20th, 2012 at 3:21 pm.
Wasting Money to Make Bad Saws
Brazing, Bad Alloy Flow
Lately I have seen a great number of saw blades where braze alloy is being wasted. Some of these are on custom-built and mil saws but it is also extremely common on factory saws from some of the biggest names in the business.
The best braze joints will have most of the braze alloy between the carbide in the steel. The braze alloy between the carbide and the steel compensates for the difference in expansion rates of the carbide and the steel. This makes the saw blade that is much tougher and helps prevent loss and breakage as well as shoulder damage. Ideally there would be braze alloy on either side of the tip running out onto the saw plate an eighth of an inch or less.
It is becoming extremely common to see saw blades were too much pressure was used to seat the saw tip. This forces the braze alloy out of the braze joint. This is a waste of braze alloy and grinding through braze alloy clogs up diamond wheels. This also greatly weakens the saw because there is not enough braze alloy between the steel and the carbide provide proper cushioning.
The tip should never be pushed into the notch. It should be placed touching the notch. This means that you want to get the saw tip and the braze alloy on the saw tip so that it is touching the steel but nothing else.
Brazing, Good Alloy Flow
The heat affected zone should end at a distance about 0.25” to 0.50” behind the saw tip. The place where the heat
affected zone ends is often referred to as a chill line.
Heating is best done through the carbide and into the steel. The steel grows 3 to 4 times as much as the carbide and putting the heat into the carbide helps compensate for this. The steel is also much more willing to receive heat than the carbide by a factor of five or 10 to 1.
