Bandsaw blades

Starrett's May 2, 2023 break-in guidance for softer materials such as carbon steel and aluminum uses normal band speed and about 50% of normal cutting rate for 50–100 square inches of cut area, followed by a gradual increase. Match the actual blade and material. Verify band speed, feed and tension separately. Starrett, break-in procedure

Specify the blade and the cutting job together

Specify band length, width and thickness, tooth geometry and pitch, material, section and machine. Starrett groups blades by material, construction and application. Starrett, bandsaw blade range

Record the welded dimensions, blade family and tooth form. Give the supplier the alloy condition, solid or hollow section, bundle arrangement, cut orientation and required finish.

Construction and tooth geometry

Common constructions solve different problems:

Starrett high-carbon construction, bi-metal construction, carbide selection, carbide grit

Tooth rake, shape, height and gullet govern how the edge enters the material and accommodates chips. A positive-rake design is different from a regular zero-rake tooth; a robust structural-cutting geometry is not necessarily the best choice for a large difficult-alloy solid. Tooth labels such as hook, skip and proprietary multi-chip designs need the supplier’s application description, not an assumed universal ranking. Starrett, tooth shapes

Pitch and set are separate. Constant pitch has uniform tooth spacing; a variable pitch such as 4–6 TPI varies tooth spacing and gullet size to reduce repetitive vibration. Set describes how teeth project sideways: raker, progressive and wavy patterns differ. A carbide triple-chip geometry may use an edge wider than the backing instead of a conventional set pattern. Starrett, pitch and set definitions

Engagement, gullets and changing sections

TPI means teeth per inch. For constant pitch, spacing in millimetres is 25.4/TPI. A first geometric estimate of teeth engaged is contact length × TPI/25.4, with contact length in millimetres. Thus, 25.4 mm of continuous contact at 6 TPI contains approximately six tooth spacings; at 12 TPI, approximately twelve. This arithmetic describes engagement, not a blade recommendation: tooth phase, variable pitch, chip formation and material behavior still matter.

Starrett gives a general rule of thumb of at least three and no more than roughly 10–14 teeth engaged, while stressing material effects. Soft, chip-loading materials can fill gullets and favor a coarser selection; difficult alloys may need more engaged teeth to take a viable chip. Treat that range as the manufacturer’s selection aid, rather than a mandatory limit for every blade technology. Starrett, material and engagement guidance

For a tube, the outer diameter alone does not describe the cutting contact. The blade transitions through walls and interrupted regions; a bundle adds both individual sections and an overall packed section. Starrett’s tube/profile chart uses outside dimension and wall thickness, separately from its solid-section chart. Consult the appropriate chart and consider the complete cut, not just the easiest point of entry. Starrett, section-based pitch selection

Machine compatibility and a named example

Use the machine manual for permissible length, width and thickness, tension and guide setup. Starrett explicitly directs users to the machine specification for length and width; contour work on a vertical saw also requires a width compatible with the intended radius. Do not assume that a larger blade fits merely because its welded length is correct. Starrett, blade dimensions and contour guidance

Starrett TENNAX-PRO illustrates a bounded structural-cutting choice: it is an M42 bi-metal family aimed at pipes, tubes, structurals, small solids and bundles. Its product page lists a 1 inch × 0.035 inch size with pitches including 4–6 and 8–12 TPI. Those are available configurations, not a recommendation for an unspecified tube. Select length for the machine and pitch from the actual section and application. Supplier metric descriptions are nominal product sizes; do not replace the ordered catalogue designation with an arithmetic conversion. Starrett, TENNAX-PRO configurations

Speed, feed, tension and break-in

Band speed is the blade’s linear travel speed; feed is its advance into the work. Both interact with pitch, material, section and blade construction. Bahco’s March 2026 catalogue provides different speed-selection tables for bi-metal and carbide blades and distinguishes material groups and section sizes. Start with the applicable supplier data and machine capability, then assess the cut. Do not copy a carbide speed into a bi-metal process or treat a feed-pressure dial as a measured cutting rate. Bahco catalogue, technical information

Tension is likewise machine- and blade-dependent. Bahco calls for measurement with a tension meter, checking actual band speed, correctly adjusted chip brushes and suitable coolant concentration and delivery. These controls belong to the cutting system; a more expensive blade cannot compensate for a worn guide or ineffective chip removal. Bahco, process checks, p. 18

Starrett gives different break-in guidance for hard materials. Use the procedure for the actual blade, especially carbide or specialty blades. Track accumulated cut area. Starrett, break-in procedure

Diagnose the system before replacing like for like

Starrett’s Bulletin 1037, footer 08/17, maps similar symptoms to multiple possible causes:

The symptom narrows an investigation; it does not establish a single cause. Record where the damage began, its relation to the weld or tooth edge, workholding, chips and recent process changes. Starrett reference guide, troubleshooting

Related reference

Cutting and shaping processes