Blade Ejector Pins (Flat Ejector Pins) — Pack of 5

Blade (flat) ejector pins for injection molds, sold in packs of 5. Used where a round pin will not fit or will not eject — thin ribs, deep narrow bosses, and the tight corners a round pin cannot reach without leaving a witness on a visible face.

How the size is written

We use W × P × D × L, matching the standard blade-pin ordering convention:

So W1.5 × P4 × D5 × L200 is a 1.5 × 4 mm blade on a Ø5 shank, 200 mm overall. All dimensions in millimetres. The blade section runs a standard length from the working end; if your plate stack needs a specific blade length (N), tell us and we will confirm it before cutting.

Getting the blade orientation right

A blade pin only works if the flat is aligned with the rib it ejects. That means it has to be keyed or pinned against rotation — a blade pin dropped into a round hole with no anti-rotation feature will turn, and the first time it turns it will either shear the rib off the part or jam against the core.

If you are fitting blade pins to a plate that previously carried round pins, budget for the anti-rotation work as part of the job, not as an afterthought. The commonest arrangement is a flat ground on the head seating against a matching flat in the retainer plate.

Why blade pins break where they do

Blades fail at the step between the flat and the round shank, not in the middle of the blade. That is the stress concentration, and it is why the shank diameter matters as much as the blade size: a 1 mm blade on a Ø5 shank survives longer than the same blade on a Ø4, because the step is gentler.

If you are replacing blade pins more than once a year, the fix is usually a larger shank or a slightly thicker blade rather than a harder pin. Going harder at the same geometry makes them snap sooner, not later.

Material and hardness

Blade pins are made in two treatments, and they behave differently:

• Nitrided SKD61 — hard case over a tougher core. More forgiving of the side loads and slight misalignment blade pins tend to see.
• Through-hardened SKD61 — hard throughout, typically in the high 40s HRC for blade sections. Better wear life, less tolerance for shock.

We confirm which treatment and what hardness you are getting in writing before your order ships. Tell us the resin and roughly how many shots the tool runs, and we will tell you which one we would fit. We would rather confirm the figure against the batch than publish a hardness you might specify a tool around.

Specifications

Not every W / P / D combination exists — the size selector shows only what is actually made. Blade thickness and blade width are matched to the shank, so you cannot put an 8 mm wide blade on a Ø4 shank.

Cutting to length

Blade pins are supplied at nominal length and cut at the head end to fit. Never shorten a blade pin from the blade end — the blade profile and its radius into the shank are ground, and cutting there removes the geometry the pin depends on.

Need a size that is not listed?

W0.8 blades, specified blade lengths (N), non-standard head sizes such as 8 × 5 and 8 × 6, and lengths outside 150–250 mm are all made to order. Request a quote with your W × P × D × L, or send a photo of the broken pin next to a caliper — for blade pins, a photo of the blade end is usually more useful than a drawing.

Shipping

International freight is calculated on packed chargeable weight. Blade pins are packed in rigid tubes with the blade ends protected. See Shipping & Delivery for destinations and transit times. Import duties and taxes are the buyer's responsibility.