Customer review 9.6!Cutting stainless steel and steel with a bandsaw: tooth pitch, speed and cooling
Cutting stainless steel and steel with a bandsaw: M42 or M51, the tooth pitch for tube, profile and solid bar, and why stainless needs a lower speed.
Stainless steel and steel are cut with a bimetal bandsaw blade. For ordinary steel and stainless steel that is the Bimetal M42, for hardened steel and titanium the Bimetal M51. The main difference between stainless and ordinary steel is the speed: according to our table you cut stainless steel at 30 to 50 metres per minute and ordinary steel at 60 to 80.
M42 or M51?
Both are bimetal blades: high-speed steel teeth with cobalt on a spring steel back. The M42 has 8 percent cobalt in the tooth tip, the M51 10 percent. That makes the M51 more wear-resistant, for hardened steel, titanium and other exotic metals. For structural steel, stainless steel, aluminium and brass, the M42 is the standard.
We make the M42 from 6 to 34 mm wide and the M51 only in 27 and 34 mm, for larger metal bandsaws. If you use a cordless bandsaw from, for example, Bosch, DeWalt, Makita, Milwaukee or Parkside, there is the Bi-Metal M42 Cordless in 13 mm wide.
Which tooth pitch for tube, profile and solid material?
With metal, the tooth pitch depends on the shape. For tube and profiles, look at the wall thickness; for solid round bar, the diameter; for solid rectangular material, the dimension you cut through. Most bimetal blades have a variable tooth pitch, such as 6/10: the distance between the teeth varies within that range, which helps against vibration.
These are the tables that come with our bimetal blades, combined. Dimensions are in millimetres.
| Tooth pitch | Tube and profile (wall thickness) | Solid round (diameter) | Solid rectangular |
|---|---|---|---|
| 24 TPI | - | up to 2 | up to 2 |
| 14 TPI | up to 2 | 2 to 7 | 2 to 5 |
| 10/14 TPI | 2 to 2.5 | 7 to 10 | 5 to 10 |
| 8/12 TPI | 2.5 to 4 | 10 to 15 | 10 to 13 |
| 6/10 TPI | 4 to 5 | 15 to 20 | 13 to 18 |
| 5/8 TPI | 5 to 7 | 20 to 25 | 18 to 25 |
| 4/6 TPI | 7 to 15 | 25 to 50 | 25 to 50 |
| 3/4 TPI | 15 to 27 | 50 to 127 | 50 to 115 |
| 2/3 TPI | 27 to 50 | 127 to 254 | 115 to 180 |
| 1.1/1.5 TPI | over 50 | over 254 | over 180 |
We don't make everything in the table in bimetal. The M42 comes in 2/3 to 10/14 TPI, and in 13 mm wide also with a constant pitch of 4, 6 and 18 TPI. We don't make a constant 14 or 24 TPI, nor 1.1/1.5 TPI. The M51 comes in 2/3, 3/4 and 4/6 TPI. If your work falls in a row we don't make, call or email us. How tooth pitch and the number of teeth relate is explained in choosing the tooth pitch.
A tooth pitch that is too coarse on thin tube can snag and lose teeth. One that is too fine on solid material can clog with chips and heat up.
Speed: stainless steel is the slowest
From our cutting speed table, for bimetal:
| Material | Cutting speed (m/min) |
|---|---|
| Stainless steel | 30 to 50 |
| Steel | 60 to 80 |
| Carbon steel (the metal) | 60 to 90 |
| Copper | 80 to 300 |
| Aluminium | 100 to 700 |
Many grades of stainless steel harden when the tooth rubs over them instead of taking a chip. So keep the blade speed within the range in the table and use an even, sufficient feed, so the teeth keep cutting.
Cooling
Cooling carries away heat and chips. On a machine with a coolant system, use a coolant such as Ecocool EM-E, for steel, non-ferrous metals and stainless steel. If your machine works with a mist system, there is mist oil: an oil you don't mix with water, for steel, alloy steel, stainless steel and aluminium.
Tension and thickness
For the M42 and M51 our tension table gives 25,000 to 30,000 PSI, against 15,000 to 20,000 PSI for Flexback carbon steel. Too little tension can make the blade wander in the cut.
The thickness of the M42 depends on width and tooth pitch: 6 and 10 mm are 0.65 mm, 19 and 27 mm 0.90 mm, 34 mm 1.10 mm, and in 13 mm it is 0.65 or 0.90 mm depending on the tooth pitch. We recommend the 0.90 mm versions from 2,000 mm length.
Blunt? Then a new one
We don't resharpen bimetal blades; when one is blunt, you order a new one. Your previous orders, with all sizes, are in your customer account. For larger quantities, contact us. Other materials are covered in which bandsaw blade for which material; all blades for metal are in the Metal collection.