Hacksaw blades are chosen by tooth pitch, blade material, and exact frame fit — a 14 TPI blade shears thick bar while a 24 TPI blade glides through thin tubing.
Get it wrong and a cut is ruined in seconds: too coarse on thin conduit, teeth catch and snap; too fine on thick bar stock, gullets pack with chips and the blade stops cutting. Choosing among the types of hacksaw blades comes down to three things — tooth pitch, steel grade, and physical fit — each with a clear rule.
What Are The Main Types Of Hacksaw Blades?
Hand hacksaw blades fall into three material classes: carbon steel (economical, for soft metals and plastic), high-speed steel (harder edge for tougher metals), and bi-metal (HSS teeth on a flexible backing for longer tooth life).
- Carbon steel: Stanley’s 15-924A is a 12-inch, 24-TPI high-carbon-steel blade for soft metals and plastic. Cheap and sharp, but dulls faster on hard stock.
- High-speed steel (HSS): Stanley’s 15-828A is a 12-inch, 18-TPI HSS blade with ground teeth, for most metals including unhardened tool steel and stainless steel.
- Bi-metal: HSS teeth welded to a flexible back — tougher, longer-lasting, the general-purpose pick for several jobs.
- Power-hacksaw blades: A separate category specified by length, width, thickness, and TPI — documented examples at 12, 14, and 17 inches long, 1 or 1¼ inches wide, 0.050-inch thick, commonly 10 or 14 TPI. Never substitute one in a hand frame.
Tooth form matters too: regular teeth are general-purpose on ferrous metals, skip-tooth clears chips in softer material, and hook teeth appear mainly on power-saw blades.
Which Tooth Pitch (TPI) Should You Choose?
The rule: at least three teeth in contact with the workpiece at all times. Too coarse catches and strips teeth on thin stock; too fine clogs with chips in thick stock.
| Tooth Pitch | Best For | Watch Out For |
|---|---|---|
| 14 TPI | Thick solid bar, thick-wall pipe, large sections | Mostly a power-hacksaw pitch |
| 18 TPI | Mild-steel bar, pipe, flat bar, angle iron, many stainless sections | Slow going on thin sheet |
| 24 TPI | Sheet metal, thin-wall pipe, box section, conduit walls around 2–6 mm | Can snag on very thin stock |
| 32 TPI | Thin-wall tubing, copper pipe, electrical conduit, material under about 2 mm | Clogs in thick bar stock |
The Canadian Centre for Occupational Health and Safety recommends 18–32 TPI for thinner metal or plastic around 0.5 cm (¼ inch), saving coarse blades for thicker stock. Its hand saw safety guidance also recommends light machine oil on the blade to reduce overheating and breakage — a cheap habit that extends blade life.
Will A Replacement Blade Actually Fit Your Frame?
The most common length is 12 inches (300 mm); compact saws may take 150-mm blades. Length alone doesn’t guarantee fit — match width, thickness, and mounting-hole arrangement to the frame. A 12-inch blade isn’t automatically compatible with a compact frame, and power blades never belong in a hand saw. Stanley’s STHT20138 12-inch D-shaped hacksaw, for example, ships with a 24-TPI × 12-inch carbon-steel blade — a sensible default for light metal and plastic. When stocking up, this roundup of the best hacksaw blades for cutting metal narrows the field by material and pitch.
Which Mistakes Break Blades Fastest?
Most failures trace to pitch mismatch or too much force, not defective steel. Excessive pressure raises the odds of tooth damage, overheating, breakage, and lost control — let the teeth cut with controlled strokes. Two more traps: choosing by length alone while ignoring width, thickness, and mounting holes, and mixing hand-saw pitches (18–32 TPI) with power-saw pitches (commonly 10 or 14 TPI). Inspect blades before each use, wear eye protection, keep hands clear of the cutting path, and discard any blade that is bent, dull, missing teeth, or no longer cutting straight.
Common Questions
Is 18 TPI Or 24 TPI Better For Cutting Metal?
It depends on section thickness. 18 TPI handles mild-steel bar, pipe, angle iron, and many stainless sections; 24 TPI suits sheet metal, box section, and conduit walls around 2–6 mm. Pick whichever keeps at least three teeth engaged across the cut.
Can I Use A Power-Hacksaw Blade In A Hand Saw?
No. Power-hacksaw blades differ in length, width, and thickness — documented examples run 12 to 17 inches long and up to 1¼ inches wide, far outside a hand frame’s capacity. Use a blade specified for your hand saw.
How Do I Know A Replacement Blade Fits?
Match length, width, thickness, and mounting-hole arrangement to your frame. The most common hand-hacksaw length is 12 inches, but compact saws may take 150-mm blades — measure before buying and check the frame’s stated capacity.
Sources
- Stanley Tools. “12 in 24 TPI High-Carbon Steel Hacksaw Blade” Product specification for the carbon-steel blade cited above.
- Stanley Tools. “12 in x 18 TPI High Speed Steel Hacksaw Blade” Product specification for the HSS blade and its specified materials.
- Canadian Centre for Occupational Health and Safety. “Hand Saw Safety Guidance” Supports the TPI ranges for thin stock, oiling, and safety practices.