Fish Slicer Blades — Made to Your Measurement, Not to a Size List
The oblique slicers built in Foshan and Xingtai, the portioning heads on European lines, and the single-head machines still running in small plants all take the same kind of blade: a long, thin, plain strip clamped along its back edge, with no mounting holes. Length is set by the span of the cutting head, width by the clamp bar, thickness by the cut — and none of those three is standard across builders, generations, or even the same model after a rebuild.
So we do not publish a size list, and we do not sell a “standard” blade. Send the three measurements from the blade you run now — a 470 × 18 × 0.8 mm strip off a portioning head is one order we make, and the next enquiry may be twice that length. Same drawing process, same lead time.
The blade, in general terms
There are only five things to fix, and four of them come off your old blade with a caliper and a rule. What follows is how each dimension behaves — not a table of numbers to order from, because a table would be wrong for most machines in service.
| Feature | What decides it | What it changes |
|---|---|---|
| Length | The span of the cutting head, tip to tip | Stiffness and deflection: a longer blade needs more thickness or more tension in the clamp |
| Width | The clamp bar and how much strip stands proud of it | How much blade is available for re-honing over its life; too narrow and it is scrapped early |
| Thickness | The cut, the product and the machine's clamp | Cutting force, flatness, edge angle and how the edge behaves on bone |
| Mounting | The holder: plain strip, slots, or a drilled pattern | Whether the blade sits flat and repeats its position after a change |
| Edge | The fish and the product state | Bevel angle, honing, and how clean the cut face comes out |
Thin gauge: what under 1 mm changes
Slicer blades usually run between 0.5 and 1.5 mm. In that range the blade stops behaving like a block of steel and starts behaving like a spring, and three things follow. They explain almost every complaint about these machines.
| Property | Consequence | What we control in grinding |
|---|---|---|
| Flatness | A blade that is not flat bows in the clamp and cuts a wedge instead of a slice | Stress-relieved strip, ground flat before the edge is put on, checked on a surface plate |
| Edge angle | A 25–30° edge on thin strip leaves almost no body behind the edge and rolls on the first bone | 15–18° for fresh fish, 20–22° for frozen or partly thawed blocks |
| Straightness of the edge line | A wavy edge leaves torn fillets and a thickness that varies along the cut | Edge line held within 0.05 mm over the full length |
A thicker blade is not automatically the fix. Going up a gauge stiffens the blade but raises cutting force, distorts thin fillets, and on many machines fouls the comb or the clamp. If the blade is bowing, the cause is usually flatness or clamp torque rather than gauge. That is worth checking before you change the specification.
Steel and edge for food contact
| Grade | Hardness | Where it fits |
|---|---|---|
| 420J2 (3Cr13) | HRC 50–54 | Standard choice for soft, oily fish: corrosion resistance first, easy to re-hone, forgiving in thin gauge |
| 5Cr15MoV | HRC 52–56 | General workhorse for snakehead, carp and white fish: better edge retention without losing toughness |
| 440C (9Cr18MoV) | HRC 54–56 | Higher wear resistance for high-volume lines and bony species; still workable in thin gauge |
| Carbon steel | HRC 56–60 | Sharpest edge, but only for a dry line with a fixed cleaning schedule — not for a wet fish room |
| Your grade | as specified | Named on your drawing, or matched from the mill certificate of the blade you buy today |
Hardness and gauge move together. On a strip under 1 mm we stop around HRC 56 on purpose: harder than that and the edge micro-chips the first time it meets a rib bone, and a chipped thin blade cannot be ground back to a usable edge — you lose the blade, not just the edge. At this gauge, corrosion resistance and toughness buy more service life than hardness.
If your plant has an approved steel list or a hygiene specification, send it. The quotation is written against it, and the grade is confirmed in writing — “stainless” alone does not tell you whether you are getting 420J2 or 440C.
Measure before you order
| # | Measure | Why |
|---|---|---|
| 1 | Overall length, tip to tip | Set by the head span, and the first thing a copy or a rebuild changes |
| 2 | Width of the strip, back edge to cutting edge | Set by the clamp bar; a 1 mm error shows up as a blade that sits proud or buried |
| 3 | Thickness with a caliper, at three points | Worn blades measure thin at the edge; read the back third |
| 4 | Photograph the old blade on a rule, both faces | Shows which face carries the bevel and how much of the width is ground |
| 5 | Machine plate, and the comb (blade guard) in place | Confirms the blade clears the comb fingers at full stroke |
Send the old blade measurements
Failure modes, and what each one means
The edge rolls over instead of wearing
Edge angle too shallow for the product, or the blade is meeting frozen fish. Move to 20–22° and confirm the fish is fully thawed. On thin strip there is very little steel to support a fine edge.
The cut is clean at one end and torn at the other
Blade not flat, or clamp torque uneven along the bar. Check flatness on a surface plate before blaming the edge; re-torque the clamp from the centre outwards.
Fillets come out wedge-shaped
The blade is sitting at an angle in the clamp, or the comb is holding the fillet away from the blade. Measure the blade's projection above the clamp at both ends — it should be identical.
Rust spots along the clamp line
Crevice corrosion where product sits between blade and clamp. It is a cleaning problem, not a steel problem; a 440C blade survives it longer but will not prevent it.
What we make — and what we do not
| Item | We make it | Note |
|---|---|---|
| Long thin slicer blade, any length, width and thickness | Yes | 420J2, 5Cr15MoV, 440C or your grade; single bevel; plain strip or drilled to your pattern |
| Matched sets for one head or several stations | Yes | Same batch, same drawing, so the blades arrive identical |
| Blade comb / guard fingers | No | Not a blade — source from the machine builder |
| Scaler rollers, bone saws, skinning blades | No | Different product families, different machines |
Ordering
- You send the three measurements, a photo of the old blade on a rule, the machine model and the quantity.
- We reply within 24 hours with a drawing, the steel grade, the edge angle, a price and a lead time.
- You approve the drawing — one piece is a valid first order.
- We grind and pack in a rigid case with the edge protected, drawing reference marked on the case.
Related: Fish slicing blades overview · Edge angle, steel and failure modes · All machine brands
Machine brand names are used only to describe compatibility. We are not affiliated with, or an authorised distributor of, any machine builder.