What TPI band saw blade for solid bar, tube, profiles and bundles? TPI chart in mm and inch, variable pitch, plus speed, feed and tension starting points.
Updated October 2026
Quick answer: TPI (teeth per inch) is how many teeth sit in one inch of blade. Choose it so roughly 3–6 teeth are in the cut: coarse pitch for thick solids, fine pitch for thin walls and small sections, variable pitch for tube, profiles and bundles. Treat charts as starting points and adjust by chips, sound and finish.
Send one current blade spec and the material it cuts. Include width × thickness, length (for loops), current TPI, material and section, machine model, quantity and country. Use the RFQ form, WhatsApp +86 131 7575 3620 or sales@lizensaw.com. We reply with a practical starting recommendation.
What TPI Means (and How to Count It)
TPI, or teeth per inch, decides how many blade teeth share the cut at one time. To count it, mark a point on the blade and count tooth tips over 25.4 mm (1 inch). A variable-pitch blade written as “4/6” alternates its spacing between 4 and 6 TPI along the band.
This guide is a practical starting point for M42 and M51 bi-metal band saw blades. The final selection still depends on the material, section shape, machine condition, coolant and feed setup.
The Working Rule: 3–6 Teeth in the Cut
Keep roughly three to six teeth in contact with the material during the cut.
If too few teeth are engaged, each tooth takes too heavy a bite. The result can be stripped teeth, broken teeth or a rough cut. If too many teeth are engaged, the gullets can fill with chips. That creates heat, rubbing and premature dulling.
Example: on a tube with a 3 mm wall, the blade only touches 3 mm of steel at each wall. A coarse pitch would leave one tooth or none in the cut, so a fine pitch is needed to keep at least three teeth spanning the wall.
Starting TPI Chart (mm)
Use these ranges as a first check, then adjust after looking at chip shape, sound, cut finish and blade wear.
| Material or section | Starting TPI range |
|---|---|
| Solid bar under 25 mm | 6-10 TPI |
| Solid bar 25-75 mm | 4-6 TPI |
| Solid bar over 75 mm | 2-4 TPI |
| Thin-wall tube under 3 mm wall | 14-18 TPI |
| Tube or hollow section, 3-8 mm wall | 8-12 TPI |
| Heavy tube or structural section over 8 mm wall | 6-8 TPI |
| Angle, channel and mixed structural profiles | 6-10 TPI |
| Aluminium profiles | commonly 3/4 or 4/6 variable pitch |
Inch-Based Charts: a Cross-Check
Several blade makers publish inch-based pitch charts grouped by solid size only. For example, the sawblade.com Band Saw Blade Speed and Feed Chart (bi-metal, credit: sawblade.com) suggests fine variable pitches for work up to about 1 inch, mid-range variable pitches for 1–3 inch, coarser pitches for 3–6 inch and the coarsest variable pitches above 6 inch. Its suggestions for the 1–3 inch band run somewhat finer than the 25–75 mm row above. Makers’ charts differ, and they differ by tooth form, so use one chart consistently and adjust by results. For tube and profiles, use the mm chart above.
Variable Pitch or Constant Pitch
Constant pitch, such as 6 TPI, keeps the same tooth spacing along the blade. It is often suitable for solid material where the blade stays in continuous contact.
Variable pitch, such as 4/6 TPI, alternates the spacing. It is useful for tube, profiles, bundles and applications where the blade enters and exits the material repeatedly. The varied spacing helps reduce vibration and can give a smoother cut in interrupted sections.
Tube, Profiles and Bundles
For tube and profiles, select pitch from the wall or flange thickness, not the outside size. Variable pitch usually runs smoother because the blade enters and exits the material repeatedly.
For bundles, do not select TPI from the outside diameter of the bundle alone. The blade is not cutting one solid piece; it is entering and leaving many smaller sections.
Start from the size or wall thickness of the individual piece, then often move one step finer. This keeps enough teeth engaged during the interrupted cut and reduces tooth shock.
Stainless Steel: Pitch First, Grade Second
For stainless steel, do not choose grade and TPI separately. A thick stainless solid bar may justify M51 and a coarser pitch. A thin-wall stainless tube usually needs a finer pitch first; changing from M42 to M51 will not fix a poor TPI match. For grade choice, see M42 vs M51 bimetal blades.
Stainless is also run at a slower band speed than carbon steel; see the starting points below.
Band Speed, Feed and Tension: Starting Points for Bimetal (M42/M51) Blades
These are published starting values from other makers, not LIZEN test data. Always follow your saw maker’s manual and your blade supplier’s chart, then adjust by chip shape and sound.
Band speed by material
The DoALL Saw Blades Catalogue 2026 (page 6, “Band speed & group selector”; credit: DoALL) groups materials and gives band speed in m/min by section size. In its chart, plain structural steels such as St37/AISI 1015 get the highest starting speeds; medium-carbon steels such as C45/AISI 1045 and alloy steels such as 42CrMo4/AISI 4140 start noticeably lower; austenitic stainless 304 lower again, and 316 lowest of these. Larger sections generally start slower than small ones.
The sawblade.com Band Saw Blade Speed and Feed Chart (credit: sawblade.com) shows the same order in imperial units: band speed in SFPM (surface feet per minute) and cutting rate in SIPM (square inches per minute). Low-carbon steel runs fastest with the highest cutting rate, chrome-moly and higher-carbon steels lower, and 300-series stainless much slower with a very low cutting rate, especially 316. The two sources use different units and test bases, so do not convert or merge them into one number.
Feed
Feed controls chip thickness (summary of the mechmeld guide to choosing metal-cutting bandsaw blades; credit: mechmeld). Fine dust means rubbing: feed too light or pitch too fine. Heavy blue chips, loud vibration or stripped teeth point to too much feed or speed, poor coolant, wrong TPI or loose clamping. Curled chips and a steady sound mean the cut is healthy. On stainless, keep the feed steady so the teeth cut instead of rubbing.
Blade tension
Correct tension increases with blade width and thickness. The ARNTZ tension gauge operating instructions (credit: ARNTZ) list recommended ranges in MPa and PSI for each blade size, from narrower 20 mm blades up to 80 mm wide blades, and warn that wrong tension can cause crooked cuts or blade breakage. Use their table or your saw maker’s value.
- Switch the machine off and fit the tension gauge on the back of the blade.
- Zero the gauge on the slack blade.
- Tension the blade until the gauge reads the recommended value, then remove the gauge.
New standard bimetal blades are usually broken in at reduced feed first.
Send one current blade spec and the material it cuts. Include width × thickness, length (for loops), current TPI, material and section, machine model, quantity and country. Use the RFQ form, WhatsApp +86 131 7575 3620 or sales@lizensaw.com. We reply with a practical starting recommendation.
Reading Problems: TPI or Setup?
Stripped or broken teeth near the root usually means the pitch is too coarse for the section, the feed is too aggressive, or the blade was not broken in correctly.
Smooth, glazed or blunt teeth with little visible damage can mean the pitch is too fine, the feed is too light, or chips are packing in the gullets.
A diagonal cut is usually not solved by changing TPI first. Check blade tension, guides, machine alignment and tooth condition before blaming pitch.
| Symptom | Likely TPI cause | Likely setup cause |
|---|---|---|
| Stripped or broken teeth | Pitch too coarse for the section | Feed too aggressive, no break-in, loose clamping |
| Glazed or blunt teeth, fine dust | Pitch too fine, packed gullets | Feed too light, speed too high |
| Diagonal or crooked cut | Rarely the first cause | Blade tension, guides, alignment, worn teeth |
| Vibration and noise | Constant pitch on interrupted sections | Speed, clamping, guide position |
| Fast wear on stainless | Pitch mismatch for wall/section | Band speed too high, coolant, rubbing feed |
What to Send LIZEN for a Spec Check
When a distributor or welding center asks LIZEN to review a blade specification, one complete current size is better than a full catalogue request. Send:
- blade width and thickness;
- blade length if welded loops are required;
- current TPI or tooth form;
- material and section being cut;
- machine model or cutting setup if known;
- current band speed and feed if known;
- whether you need coil stock or welded loops;
- expected monthly or annual usage.
Buying from LIZEN
LIZEN supplies M42/M51 bi-metal band saw blades as coil stock (MOQ 1,000 m) for local welding centers, and as welded loops (300 loops for a first trial order; mixed sizes allowed). A controlled sample test can be discussed. Not sure of the blade size? Try the Blade Selector or the Download Center.
FAQ
What does TPI mean on a band saw blade?
TPI means teeth per inch: the number of tooth tips in 25.4 mm of blade. A constant-pitch blade such as 6 TPI has even spacing. A variable-pitch blade such as 4/6 alternates spacing between 4 and 6 TPI. Lower numbers mean coarser teeth and larger gullets; higher numbers mean finer teeth.
How many teeth should be in the cut?
As a working rule, keep roughly three to six teeth in contact with the material. Too few and each tooth takes too heavy a bite, which can strip teeth. Too many and the gullets pack with chips, causing heat, rubbing and early dulling.
What TPI should I use for thin-wall tube?
Thin wall needs a fine pitch so at least three teeth span the wall. As a LIZEN starting point, tube under 3 mm wall is commonly 14-18 TPI and 3-8 mm wall 8-12 TPI. Variable pitch helps because the blade enters and exits the wall repeatedly.
When should I use variable pitch?
Use variable pitch for tube, profiles, bundles and other interrupted cuts, and when vibration or noise is a problem. Constant pitch is often suitable for solid material where the blade stays in continuous contact.
What TPI should I use for cutting bundles?
Do not choose TPI from the outside size of the bundle. Start from the size or wall thickness of one individual piece, then often move one step finer, so enough teeth stay engaged through the interrupted cut.
What band speed for stainless steel with a bimetal blade?
Run stainless slower than carbon steel. Published starting charts such as the DoALL Saw Blades Catalogue 2026 and the sawblade.com Band Saw Blade Speed and Feed Chart list austenitic grades like 304 and especially 316 well below structural steel. Treat these as starting points, follow your saw manual and adjust by chips.
How tight should a band saw blade be?
Tension rises with blade width and thickness. The ARNTZ tension gauge operating instructions give recommended ranges by blade size and explain measuring with a tension gauge. Wrong tension can cause crooked cuts or blade breakage. Always follow your saw maker’s manual.
Will an M51 blade fix a bad TPI choice?
No. A higher grade does not correct a pitch that is too coarse or too fine for the section. Choose TPI first, then grade. See M42 vs M51 bimetal blades for grade choice.
What MOQ does LIZEN have?
Coil stock: 1,000 m per material and width. Welded loops: 300 loops for a first trial order, and mixed sizes are allowed. Contact WhatsApp +86 131 7575 3620 or sales@lizensaw.com.
Send one current blade spec and the material it cuts. Include width × thickness, length (for loops), current TPI, material and section, machine model, quantity and country. Use the RFQ form, WhatsApp +86 131 7575 3620 or sales@lizensaw.com. We reply with a practical starting recommendation.