Comparison Guide4 min read

D-Type vs Rectangular Ejector Blade: Installation Comparison

Key Takeaway: D-type blades install into standard round bores (5 min/bore) with a set screw for anti-rotation. Rectangular blades require EDM/wire-cut rectangular bores (30–45 min/bore) but provide absolute anti-rotation.

Installation Comparison

Factor	D-Type Blade	Rectangular Blade
Bore type	Round H7 (standard drill + ream)	Rectangular (EDM or wire-cut)
Machining time/bore	5–10 min	30–45 min
Tooling required	Standard H7 reamer + M3 tap	EDM electrode or wire-cut setup
Anti-rotation	Set screw (functional, may loosen)	Form-fit (absolute, permanent)
Installation time/blade	15 min (bore + set screw)	45–60 min (EDM bore + blade fit)
Replacement ease	Easy (unscrew, swap, re-align)	Easy (drop-in, form-fit)

Frequently Asked Questions

Can D-type blades retrofit into existing round bores?+

Yes — if the existing round bore diameter matches the D-type blade OD. The only addition is a tapped hole for the anti-rotation set screw. This makes D-type the easiest blade to retrofit into an existing mold.

What is the price difference?+

D-type blades are 10–15% cheaper than rectangular blades due to simpler manufacturing. The bigger savings come from bore preparation: round bores cost 80% less to machine than rectangular bores.