Home Products Shredder Blades

Shredder Blades

A shredder blade is a precision-machined cutting knife mounted on the rotor shaft of an industrial shredder. Working against fixed counter-knives, shredder blades reduce oversized feed material — plastics, metals, wood, tires, and mixed waste — through a shearing or tearing action governed by blade geometry, hook angle, and cutting gap. Steel grade and heat treatment determine service life: most industrial shredder blades are machined from alloy tool steels such as D2 or H13 and hardened to HRC 55–64.

Shredder Blades We Manufacture

YISHI Machinery manufactures replacement and custom shredder blades for single-shaft, dual-shaft, and quad-shaft industrial shredders. These knives are engineered for size reduction of plastics, metals, wood, tires, and municipal solid waste in high-throughput recycling and waste processing lines. Blade bodies are typically machined from alloy tool steels such as AISI D2 (Cr12MoV) or H13, with hardness values ranging from HRC 55–58 for impact-resistant cores to HRC 62–64 for high-wear cutting edges after vacuum heat treatment and multi-temper cycles. Every knife set is produced to match OEM mounting geometry—square bore, hexagonal, or keyed—with outer diameter tolerances held to ±0.02 mm on critical seating surfaces.

Vacuum Heat-Treated Tool Steels
Blades are hardened to HRC 58–62 on D2/Cr12MoV substrates, with optional cryogenic treatment to transform retained austenite for dimensional stability in high-cycle applications.
Precision-Ground Cutting Edges
Edge radii are ground to 0.01–0.03 mm on CNC grinders, ensuring clean shear cuts and reducing the regrind frequency in abrasive feedstocks like glass-filled nylon or e-waste.
Multiple Mounting Configurations
Bores are available as square (e.g., 40×40 mm, 60×60 mm), hexagonal, or keyed round to match Vecoplan, WEIMA, Untha, or Doppstadt shaft interfaces without adapter plates.
Wear-Resistant Coatings
Optional TiN, TiCN, or CrN PVD coatings with microhardness up to HV 2500 can be applied to extend service life when processing highly abrasive materials such as sand-contaminated wood or fiberglass.
Counter-Knife and Bed Knife Sets
Fixed counter-knives are supplied in matched sets with the rotor blades, ground to a flatness of 0.03 mm over 300 mm length to maintain a consistent cutting gap of 0.1–0.3 mm.
Full OEM Cross-Reference Support
Manufacture to drawing or sample. Provide your OEM part number, shaft diameter, and number of hooks, and YISHI will reverse-engineer the knife profile with a material cert and hardness test report.

Take a Closer Look

Plastic Recycling
Scrap Metal Processing
Tire and Rubber Shredding
Wood and Biomass Grinding
Municipal Solid Waste (MSW)
E-Waste and WEEE Recycling

Plastic Recycling
Single-shaft shredder blades for size reduction of HDPE drums, PP purgings, and PET bottles. D2 blades at HRC 60–62 provide resistance to adhesive wear from molten polymer smearing.
Scrap Metal Processing
H13 or M2 steel blades for shearing aluminum castings, copper wire, and light-gauge steel sheet in dual-shaft shredders. Impact toughness prevents chipping on unshreddable tramp metal.
Tire and Rubber Shredding
Tungsten carbide-tipped blades for primary tire shredders processing steel-belted radial tires. The carbide insert maintains a sharp edge through rubber compound and steel cord at throughputs exceeding 5 tonnes per hour.
Wood and Biomass Grinding
H13 hot-work tool steel blades for high-speed wood chippers and pallet shredders. The material's temper resistance prevents softening during continuous operation where blade tip temperatures can exceed 200°C.
Municipal Solid Waste (MSW)
Pre-shredder blades in Cr12MoV with a tough core hardness of HRC 55–57 to survive impacts with concrete, stones, and ferrous metals in mixed waste streams before magnetic separation.
E-Waste and WEEE Recycling
Thin-kerf granulator blades for circuit board and hard drive shredding. Tight clearance of 0.05 mm between rotor and stator knives ensures liberation of precious metals without excessive fines generation.

Technical Specifications

Dimensions	OD 150–600 mm, ID/bore 30–150 mm (square, hex, or keyed), thickness 15–80 mm. Length per knife segment up to 300 mm for bolted-on designs.
Materials	AISI D2, Cr12MoV, SKD11, AISI M2, H13, 55SiCr, tungsten carbide (tipped), D2+TiN coated
Hardness	HRC 55–64 depending on material grade and application; carbide tips up to HRA 89
Tolerances	Bore tolerance H7, thickness ±0.05 mm, cutting edge straightness 0.02 mm per 100 mm
Surface Finish	Cutting edge Ra ≤ 0.4 µm; mounting surfaces ground to Ra 0.8 µm
Customisation	Manufacture to customer drawing, sample, or OEM part number. Specify number of hooks, hook angle, bolt pattern, and coating preference.

Why Choose Yishi

YISHI Machinery operates an in-house heat treatment line with vacuum furnaces and deep cryogenic capability, giving us direct control over the hardness gradient from core to cutting edge. Every batch is verified with a Rockwell hardness tester and documented on a mill test certificate. We maintain a library of over 2,000 shredder knife profiles and can match your existing knife without a drawing if you provide the machine make, model, and a worn sample. Lead times for standard D2 blades are 15–25 working days; complex carbide-tipped sets are 30–40 days. All knives are individually inspected for dimensional conformity before shipment.

Get a Quote

Frequently Asked Questions

What steel grade is best for shredding glass-filled plastics?

For glass-filled nylon or polycarbonate, we recommend D2 (Cr12MoV) at HRC 60–62 with a TiN PVD coating. The high chromium content (11–12%) provides carbide structures that resist abrasive wear, while the TiN coating further reduces the coefficient of friction. In extreme cases, a tungsten carbide-tipped blade will offer the longest service life.
Can you match blades from my existing OEM shredder?

Yes. Provide the OEM machine make and model, shaft configuration, and a worn blade sample or dimensional drawing. We will reverse-engineer the profile, including hook angle, bolt-hole pattern, and counter-knife geometry. A first-article inspection report is supplied with the trial set.
What is the typical lead time for a custom shredder knife set?

Standard D2 or Cr12MoV knife sets ship in 15–25 working days after drawing approval. Sets requiring PVD coating or tungsten carbide tipping typically need 30–40 working days. Rush orders can be accommodated with an expedite fee.
How often should shredder blades be sharpened or rotated?

Sharpening intervals depend on feedstock abrasiveness and throughput. As a general guideline, D2 blades processing clean HDPE may run 400–600 hours before requiring a 0.2–0.5 mm regrind. Blades processing metal-contaminated waste may need inspection every 50–100 hours. We offer a regrinding service with a 7-working-day turnaround.
Do you provide the counter-knives and spacers as well?

Yes. We supply complete knife sets including rotor blades, counter-knives (bed knives), and precision-ground spacers to maintain the correct cutting gap. All components are manufactured from the same material batch to ensure uniform wear characteristics.
What hardness should a shredder blade core have to prevent breakage?

For impact-prone applications like metal shredding, we recommend a differential hardness treatment. The blade core is tempered to HRC 50–54 for toughness, while the cutting edge is induction-hardened or selectively coated to HRC 60–62. This prevents catastrophic fracture from tramp metal strikes.