Knowledge base
Knowledge base
Information, guides, and tips you should know to utilize our band saw blades to their fullest potential.
In the world of woodworking there is nothing that beats a great band saw blade when it comes to precise cuts and efficient material handling. This guide helps you choose the correct blade for your next job.
Material Matters
Before looking deeper into blade types, let’s establish a solid footing. Band saw blades come in various materials, each suited for specific applications. This guide focuses on carbon steel blades, a popular and budget-friendly choice for many woodworkers. However, within the carbon steel category, the backing material makes a world of difference.
Flex Back Blade
- Key Feature: Flexibility!
The backing material of a flex back blade is unhardened (or flexible), allowing it to bend and effortlessly follow curved cuts.- Strengths: This blade excels at intricate shapes, scrollwork, and tight radius cuts in wood, metal, and even plastics. Surprisingly durable, it produces smooth finishes, making it ideal for veneers and thin materials.
- Weaknesses: Not the best choice for tough materials like thick hardwoods or metals. Limited resawing capabilities due to potential blade deflection.
Hard Back Blade
- Key Feature: Strength and stability.
The backing material of a hard back blade undergoes heat treatment for rigidity, minimizing deflection during cuts.- Strengths: Delivers precise, straight cuts – ideal for resawing thick lumber, ripping boards, and cutting through tougher materials like ferrous and non-ferrous metals. Offers exceptional strength and durability for heavy-duty tasks.
- Weaknesses: Limited flexibility makes curved cuts challenging. May produce rougher cuts compared to flex back blades, requiring additional sanding, or finishing.
Summary:
Now, let’s translate this knowledge into practical application:
- Material: What are you cutting? Flex back excels in wood, thin metals, and plastic when cutting curves. Hard back tackles thicker materials and straight cuts.
- Application: Are you crafting intricate furniture or ripping lumber? Flex back is your friend for curves, while hard back reigns supreme for straight cuts and resawing.
- Machine Compatibility: Double-check your bandsaw’s specifications for blade size and wheel diameter to ensure a perfect fit.
- Remember: Both flex back and hard back blades are fantastic options within the world of carbon steel blades. By understanding their strengths and weaknesses, you can make the best selection of blades and achieve superior results in your woodworking business. Happy cutting!
Introduction
If you’re looking to cut through tough materials with precision and efficiency, bi-metal band saw blades are the way to go. They’re super strong, durable, and versatile, making them perfect for many industrial and metalworking jobs. Among these, M42 and M51 bi-metal blades are top picks. Let’s break down what makes each one special so you can choose the right blade for your needs.
Understanding Bi-Metal Band Saw Blades
Before we dive into the comparison, here’s a quick rundown on bi-metal band saw blades. They’re made from two materials: a high-speed steel (HSS) tooth edge and a flexible spring steel backing. This combo lets the blade handle high cutting speeds, stay sharp longer, and resist breaking, making it great for a wide range of cutting tasks.
M42 Bi-Metal Band Saw Blades
M42 blades are known for their 8% cobalt content, which boosts their hardness, wear resistance, and heat resistance. They’re fantastic for cutting tough materials like stainless steel, tool steel, and nickel-based alloys. M42 blades are perfect for jobs involving interrupted cuts, tough workpieces, or high temperatures. Their excellent heat resistance means they last longer, so you won’t have to change blades as often.
M51 Bi-Metal Band Saw Blades
M51 blades take things up a notch with 10% cobalt and 10% tungsten (also called wolfram), making them even tougher. They offer better heat resistance, hardness, and wear resistance, ideal for heavy-duty cutting. M51 blades excel with exotic alloys, titanium, Inconel, and other hard-to-machine materials. They’re perfect for demanding tasks that need long-lasting blades, resistance to heat build-up, and minimal tooth wear.
Comparing M42 and M51 Bi-Metal Band Saw Blades
Both M42 and M51 blades are excellent, but here are some key differences:
- Heat Resistance: M51 blades, with more cobalt, handle heat better than M42 blades. They’re better for high-temperature cutting or heavy-duty cuts that generate lots of heat.
- Blade Life: Both blades last longer than many other types, but M51 blades generally outlast M42 blades in tough cutting tasks, making them a good choice for minimizing downtime.
- Cutting Speed: M51 blades can usually handle higher cutting speeds due to their higher cobalt content, boosting productivity and efficiency.
- Cost: M51 blades are pricier than M42 blades due to their better performance. Deciding between them depends on your specific cutting needs and budget.
Conclusion
Choosing between M42 and M51 bi-metal band saw blades depends on your cutting needs and budget. If you need excellent heat resistance, long blade life, and the ability to cut the toughest materials, go for M51 blades. If your needs are less demanding or you’re watching your budget, M42 blades offer great performance at a lower cost. Both types provide the cutting power and versatility essential for various industrial applications.
Frequently asked Questions
Most of the common questions about the use of band saws can be found here.
If you do not find the answer, please look at the ‘Known Issues‘ below or contact us at info@hakansaw.com
Check the selection of tooth type, pitch, cutting speed according to the cutting table. Reduce the load on the teeth (mm/Z).
Check the blade guide.
Check the material and clamp the material as securely as possible. When cutting batches, the end of the material should be welded.
Place the blade guide as close as possible to the material being cut. Release the blade tension if you are not using the machine for a longer period of time. Adjust the blade tension according to recommended value.
Try reducing the cutting speed and the load on the teeth. Check the cutting coolant: its oil concentration should be between 8-12%.
Reduce the feeding pressure (mm/Z). Set the blade guides as close as possible to the material. Adjust the guides. Replace them if they are excessively worn. Use the correct teeth settings. See the recommended teeth selection.
Adjust the back guides so the pressure is even.
Adjust the side guides. Replace the side guides if necessary.
Avoid this by selecting the correct blade according to product recommendations and use the recommended teeth selection. Clamp the material securely. Increase the band tension. Adjust the teeth load (mm/Z) and cutting speed (m/min) according to recommendations.
Reduce the load on the teeth. Use coarser tooth. Use the recommended teeth selection. Check the chip brush, cutting coolant and cleaning procedure.
Use finer teeth. Increase the cutting speed (m/min) but reduce the teeth load (mm/Z).
Use coarser teeth. Increase the cutting speed (m/min) and increase the teeth load (mm/Z).
Known Issues
Blade failure can it be caused by several elements and reasons.
Below are some of the most common reasons why blades fail and help you determine the causes and increase the life and improve the performance of your bandsaw blades.
If you require additional help with your blades, please contact us at info@hakansaw.com.
Description of problem:
There is a smooth wear across the tips of the blade teeth and the corners of set teeth have become rounded.
Likely causes:
- Improper break-in procedure. Makes sure you follow the recommended process for breaking new blades in.
- Too-high band speed for the type of material being cut. If the band speed is too fast, the tip of the teeth experience a higher temperature which causes faster tooth wear.
- Too low feed rate of the material being cut. This causes teeth to rub instead of piercing the material and the prolonged abrasion wears the teeth. This is common on hardened materials such as stainless steel.
- Hard or abrasive materials being cut.
- Not enough sawing fluid.
Description of problem:
Heavy wear on teeth on both sides of the band.
Likely causes:
- The back-up guides are broken, worn or missing, allowing teeth to contact side guides.
- The side guides are not suitable for the width of the saw band in use.
- The saw band has been backed out of an incomplete cut.
Description of problem:
Only one side of teeth has heavy wear markings.
Likely causes:
- Worn wheel flange, causing side of teeth to contact the wheel surface or bad tracking on a flangeless wheel.
- Loose or improperly positioned side guides.
- Blade not properly perpendicular to cut.
- Blade rubbing against the cut surface on the return stroke of machine head.
- The teeth rubbing against a part of machine such as cutting guards.
Description of problem:
Irregular tooth breakage on the tips and corners of the teeth.
Likely causes:
- Improper break-in procedure. Makes sure you follow the recommended process for breaking new blades in – see our advice here.
- Inappropriate blade selection for the application.
- Damage from handling while opening of the folded band.
- Improper positioning or clamping of the material to be cut.
- Excessive feeding rate or feed pressure.
- Hitting hard spots in the material.
Description of problem:
The fracture originates from the back edge of band. The origin of the fracture is indicated by a flat area on the fracture surface.
Likely causes:
- Excessive back-up guide “preload” will cause back edge to work harden which results in cracking.
- Excessive feed rate.
- Improper band tracking – back edge rubbing heavy on wheel flange.
- Worn or defective back-up guides.
- Improper band tension.
- Notches in back edge from handling damage.
Description of problem
Complete sections of teeth broken from the band backing.
Likely causes:
- Improper Tooth Pitch. This is the number 1 cause of tooth strippage.
- The band saw is a wood cutting saw. When running a Bi-Metal Blades at high speeds like a wood machine which runs much faster in terms of surface feet per minute tooth strippage will occur more easily.
- Teeth getting too hot, causing the teeth to strip.
- Improper or lack of break-in procedure.
- Worn, missing or improperly positioned chip brush.
- Excessive feeding rate or feed pressure.
- Movement or vibration of the material being cut.
- Improper positioning of material being cut.
- Not enough sawing fluid.
- Hard spots in the material being cut.
- Band speed too slow for the material being cut.
Description of problem:
High temperature or pressure generated during the cut bonding the chips to the tip and face of teeth.
Likely causes:
- Not enough sawing fluid.
- Worn, missing or improperly positioned chip brush.
- Inappropriate band speed.
- Improper feeding rate.
Description of problem:
Gullet area has become filled with material being cut.
Likely causes:
- The tooth pitch is too fine and so has insufficient gullet capacity.
- Feeding rate is too fast and producing too large chip sizes.
- Worn, missing or improperly positioned chip brush.
- Not enough sawing fluid.
Description of problem:
The tooth tips show a discolored surface from generating an excessive amount of frictional heat during use.
Likely causes:
- Not enough sawing fluid.
- Band speed is too high.
- Improper feeding rate.
- Band has been installed backwards.
Description of problem:
Both sides of the band have heavy wear patterns.
Likely causes:
- Chipped or broken side guides.
- Side guide may be too tight.
- Insufficient flow of sawing fluid through the side guides.
- Not enough sawing fluid.
Description of problem:
Wear patterns are near the gullet area on one side and near the back edge on opposite side.
Likely causes:
- Loose side guides.
- Chipped, worn or defective side guides.
- The band rubbing on a part of the machine.
- Guide arms spread to maximum.
- Accumulation of chips in the side guides.
Description of problem:
Heavy back-edge wear will have a polished appearance or abnormal grooves worn into surface. Swaging of corners can also occur.
Likely causes:
- Excessive feed rate.
- Excessive back-up guide “preload”.
- Improper band tracking – back edge rubbing heavily on wheel flange.
- Worn or defective back-up guides.
Description of problem:
To determine if the band broke at the weld, inspect the sides at the fracture to see if there are grind markings from the weld finishing process.
Likely causes:
- When running Bi-Metal blades at high speeds like a wood machine runs breaks can occur easily. Band saws designed for wood working run at high speeds and are running a carbon blade that has more flex.
- Any of the factors below can also cause body breaks and butt weld breaks.
Description of problem:
Heavy wear in only the smallest gullets is an indication that there is a lack of gullet capacity for the chips being produced.
Likely causes:
- Excessive feeding rate.
- Too low band speed.
- Too fine a tooth pitch for the amount of material being cut.
Description of problem:
The fracture originates in the gullet and immediately travels in an angular direction into the backing of band.
Likely causes:
- An excessive twist type of stress existed.
- Guide arms spread to capacity causing excessive twist from band wheel to guides.
- Guide arms spread too wide while cutting small cross sections.
- Excessive back-up guide “preload”.
Description of problem:
The origin of the fracture is indicated by a flat area on the fracture surface.
Likely causes:
- Excessive back-up guide “preload”.
- Improper band tension.
- Guide arms spread to maximum capacity.
- Beam bar misalignment.
- Side guide too tight.
- Worn teeth.
Description of problem:
The band does not retain its regular rounded shape while holding the sides together. The flatness has been altered during use.
Likely causes:
- Excessive band tension.
- Any band conditions which cause the band to be long or short on tooth edge.
- Cutting a tight radius.
Description of problem:
“Long” on the tooth edge is a term used to describe the straightness of the band. The teeth are on the outside of the arc when the strip is lying on a flat surface.
Likely causes:
- Side guides are too tight – causing rubbing near gullets.
- Excessive “preload” – causing the band to ride heavily against the back-up guides.
- Worn band wheels causing uneven tension.
- Excessive feed rate.
- Guide arms are spread to maximum.
- Improper band tracking – back edge rubbing heavily on wheel flange.
Description of problem:
“Short” on the tooth edge is a term used to describe the straightness of the band. The teeth are on the inside of the arc when the strip is lying on a flat surface.
Likely causes:
- Side guides are too tight – rubbing near the back edge.
- Worn band wheels causing uneven tension.
- Guide arms are spread too wide.
- Excessive feed rate.
Description of problem:
When a broken band lying on a flat surface displays a twist from one end to the other, this indicates the band flatness has been altered during use.
Likely causes:
- Too high band tension.
- Any of the band conditions which cause the band to be long or short on tooth edge.
- Cutting a tight radius.
