Spear & Jackson vs Irwin: Best Tenon Saw?

Quick verdict

Brass-back stability and resharpenable teeth make Spear & Jackson 9540B-91 Tenon Saw the better long-term pick; Irwin 12 TPI Tenon Saw is sharper and lighter for quick, precise jobs.

Also check similar comparisons:

1. Spear & Jackson 9540B-91 Tenon Saw vs. Crown 195 12″ Tenon Saw
2. Irwin 12 TPI Tenon Saw vs. Crown 195 12″ Tenon Saw

At-a-glance specs

Feature	Spear & Jackson 9540B-91 Tenon Saw	Irwin 12 TPI Tenon Saw
Blade Length	10 in (25.4 cm)	10 in (250 mm)
TPI	15 PPI (14 TPI)	12 TPI
Blade Material	Hardened and tempered carbon steel	Welded (Hardpoint)
Handle Type and Material	Wooden handle secured by rivets	Soft-grip handle (ultrasonic-welded)
Spine Type	Brass back	[Missing data]
Weight	1.27 lb (0.58 kg)	0.33 lb (0.15 kg / 150 g)

Note: We don’t test products ourselves. We review user feedback and/or community discussions to recommend top options with their necessary information. This info can be susceptible to misinterpretation.

Cutting Performance And Tuning

• Spear & Jackson 9540B-91 Tenon Saw: Stable cuts after tuning; factory set is aggressive with burs, causing rough starts until filed and reset.
• Irwin 12 TPI Tenon Saw: Cuts cleanly and stays sharp; precise tenon and mitre-box work, though thin blade can flex on long, precise strokes.

Teeth And Serviceability

• Spear & Jackson 9540B-91 Tenon Saw: Teeth aren’t hardened, so they can be reset and sharpened repeatedly; 15 PPI (14 TPI) suits smooth cuts.
• Irwin 12 TPI Tenon Saw: Hardpoint welded teeth keep an edge longer but cannot be resharpened; 12 TPI triple-ground profile aids efficient push-and-pull cutting.

Spine Rigidity And Tracking

• Spear & Jackson 9540B-91 Tenon Saw: Brass back adds heft and rigidity, helping cuts track straight with minimal effort.
• Irwin 12 TPI Tenon Saw: Lacks rigid spine strength; users report noticeable bend under heavier cuts and reduced stability on long strokes.

Handle And Ergonomics

• Spear & Jackson 9540B-91 Tenon Saw: Wooden handle can be reshaped; stock fit sits high or feels small, yet becomes comfortable after sanding to suit your grip.
• Irwin 12 TPI Tenon Saw: Soft-grip handle and angle feel secure and ergonomic, though quality varies and plastic can cause sweating for some hands.

Weight And Balance

• Spear & Jackson 9540B-91 Tenon Saw: 1.27 lb (0.58 kg); light enough for handling, with brass-back mass that stabilizes the stroke.
• Irwin 12 TPI Tenon Saw: 0.33 lb (0.15 kg / 150 g); lightweight balance improves maneuverability and reduces fatigue on small projects.

Scores snapshot

Feature (Score 1–10)	Spear & Jackson 9540B-91 Tenon Saw	Irwin 12 TPI Tenon Saw
Blade Length	4	4
TPI	10	6
Handle Design	8	8
Blade Steel	10	9
Spine	10	6
Overall Score	8.4/10	6.6/10

Who should buy which?

Buy Spear & Jackson 9540B-91 Tenon Saw if you:

• You want brass-back heft for stable, straight cuts.
• You are comfortable filing teeth and resetting.
• You value low cost relative to performance.

Buy Irwin 12 TPI Tenon Saw if you:

• You want a sharp, clean-cutting saw for precise tenon and mitre-box work.
• You prefer a lightweight, well-balanced saw for small projects.
• You value strong performance at a low price.

Don’t buy either if you:

• You have large hands and need a roomy, consistently premium handle.
• You require absolute rigidity and zero setup across all cuts.

Final verdict

• Choose Spear & Jackson 9540B-91 Tenon Saw for tuneable longevity, brass-back stability, and resharpenable teeth.
• Both deliver budget value: Spear & Jackson rewards setup with stable tracking, while Irwin 12 TPI offers sharp, lightweight convenience for precise, occasional joinery.