Blade Material Characteristics & Toughness Importance for Double-Cylinder Scrap Shears
Product Overview
Double-cylinder scrap shear blades are core cutting parts for heavy hydraulic double-cylinder shears (alligator shears, car dismantling shears). They use strong hydraulic power to cold-shear metal scrap. Their harsh working environment (high impact, high wear) means material toughness and processing accuracy directly affect machine efficiency.
Primary Applications
1. Scrap Metal Recycling
Cut structural steel (channel steel, I-beam, H-beam)
Process end-of-life vehicles (dismantle frames, bearings, wheels)
2. Demolition Projects
Demolish steel structure workshops and bridge frames
Cut thick-walled steel pipes and waste cables
3. Smelting Pre-treatment
Cut large scrap into furnace-sized pieces to boost loading efficiency
Blade Material Details
1. H13 (4Cr5MoSiV1) Hot Work Tool Steel
Key Performance
Hardness: HRC50-55 after heat treatment
Good impact resistance and high-temperature stability
Strong core toughness and easy to harden
Suitable For
Alligator shears (≥160T)
Cutting thick steel plates , round steel, alloy steel, thick-walled welded pipes
Double-cylinder scrap shear blades, hydraulic excavator shear blades, mobile scrap shear knives
Steel plate cutting blades for recycling
Advantages
Ideal for heavy-impact work
Prevents blade chipping and breaking
Versatile and easy to process
2. H13K Modified H13 Hot Work Tool Steel
Key Performance
Upgraded from H13
Keeps H13’s impact resistance, better core toughness and fatigue resistance
Easier to harden than standard H13
Suitable For
Ultra-large alligator shears (≥180T)
Cutting extra-thick steel plates, heavy alloy steel, thick-walled seamless pipes
Double-cylinder scrap shear blades, hydraulic excavator shear blades (harsh conditions)
Mobile scrap shear knives (heavy continuous work), high-demand steel plate cutting blades
Advantages
More impact and fatigue resistant than H13
20%-30% longer service life than H13 (heavy work)
Best choice for ultra-large shears and high-demand blades
3. LD Steel (7Cr7Mo2V2Si) Cold Work Tool Steel
Key Performance
Hardness: HRC60-64 after heat treatment
Much better wear resistance than regular tool steel
Uniform hardness and good core toughness
Suitable For
Medium-large alligator shears (100T-160T)
Cutting 10-30mm steel plates, rebar, rusty scrap, angle steel
Double-cylinder scrap shear blades, hydraulic excavator shear blades, mobile scrap shear knives (abrasive materials)
Steel plate cutting blades for recycling (abrasive conditions)
Advantages
Best wear resistance among the three materials
Reduces blade replacement frequency
Cost-effective for abrasive work
Blade Strengthening Process
Material performance depends on precise heat treatment. Poor processing can cut blade life by half or more.
Basic Heat Treatment Steps
Vacuum heat treatment (instead of air quenching): Reduces surface damage, ensures uniform hardness for all three materials.
Low-temperature tempering (180-220℃): Eliminates internal stress, prevents deformation/cracking, stabilizes hardness and toughness.
Blade Material Selection Tips
General use: H13 (most common and reliable)
Complex scrap/heavy work: H13K (longer life, better fatigue resistance)
Abrasive materials: LD steel (best wear resistance)
For higher needs: Contact the manufacturer for material upgrades
Common Shear Blade Types
Hydraulic scrap shear knives
Hydraulic excavator shear blades, demolition shear blades, hydraulic scissors blades
Mobile scrap shear knives, steel plate cutting blades for recycling
Core components: Upper/lower primary/secondary blades, piercing tips, guide blade, cross blade
All above can use H13, H13K, or LD steel (selected by work conditions and shear tonnage).
Why Blade Toughness Matters
Double-cylinder scrap shear blades face hundreds of tons of force per cycle. Blade toughness and hardness directly affect project time and maintenance costs.
1. For High-Impact Work
Scrap demolition has unpredictable forces.
H13/H13K have good fracture toughness: They bend slightly instead of shattering.
H13/H13K = better impact resistance; LD steel = better wear resistance (for low-impact, abrasive work).
2. Precise Heat Treatment Is Key
Heat treatment balances hardness and toughness.
H13/H13K: HRC52-56; LD steel: HRC60-64.
Without proper heat treatment, blades may chip or fracture.
3. Precision Machining for Synchronization
Double-cylinder shears need perfect jaw alignment.
CNC grinding ensures a tight fit, reducing bolt wear.
H13/H13K/LD steel have stable dimensions for consistent performance.
4. Rotatable Edges for Value
All blades have 4 usable edges.
Rotating blades quadruples their service life.
Saves cost per cut in recycling operations.
Conclusion
Downtime means lost profit. Choose blades made of H13, H13K, or LD steel (matched to your work) for long life and peak efficiency.
Material Excellence (Core Advantage)
We use high-performance alloy steels: H13 (basic), H13K (upgraded), LD (wear-resistant).
Precise heat treatment balances hardness and toughness, preventing chipping and deformation.
Our blades withstand impact and abrasion, reducing maintenance costs.
The following table summarizes the type, core characteristics and main applicable shearing materials of common blade materials:
Mechanical blades are (special wearing parts) due to different cutting products, correct and reasonable selection of materials, heat treatment hardness, grinding accuracy, packaging requirements. Please contact us before purchase and confirm whether the blade specifications materials you need are available goods.