Premium Steel Grade: Authentic W6 HSS (M2 equivalent), vacuum hardened to HRC 60+. Designed for HRB400/500 high-tensile steel bar peeling with high thermal stability. Economic Steel Grade: Cr12MoV (D2 equivalent) or DC53, vacuum hardened to HRC 56–60. Tailored for standard round bars and medium-load batch production. Configuration: 4-sided reversible block design, precision ground to ±0.02mm tolerances for universal replacement on mainstream peeling heads.
Rebar peeling blades (rib stripping knives) remove the outer longitudinal and transverse ribs of deformed steel bars, creating a cylindrical surface optimized for straight thread rolling and mechanical splicing.
1. Steel Grade & Heat Treatment Configurations
M2 High-Speed Steel (W6Mo5Cr4V2 / SKH51) | Industry Standard
Processing: Full computer-controlled vacuum quenching and multi-stage tempering to prevent temper brittleness.
Hardness:HRC 62–65.
Application: High-volume, continuous peeling for regular HRB400/HRB500 standard deformed rebars on automated processing lines. Features superior core toughness and resistance to chipping under structural shock loads compared to high-carbon high-chromium mold steels.
Processing: Vacuum hardening with controlled stress-relief tempering loops.
Hardness:HRC 58–60.
Application: Optimized for heavy scaling rebar, abrasive rust-covered steel rods, and environments dominated by severe abrasive wear where high impact stress is relatively controlled. High carbon and chromium phase matrices maximize edge retention against harsh scale abrasion.
Configuration: Sold in a matched 4-piece installation set. Each individual block insert features a square profile providing 4 independent indexable cutting edges (yielding 16 total fresh cutting faces per set).
Typical Specifications: 25×25×8 mm, 25×25×10 mm, 25×30×10 mm (Custom dimensions fully supported via CAD drawings or used physical samples).
Precision Manufacturing Tolerances:
Length, Width & Thickness:±0.03 mm for precision ground finished components (Rough ground unfinished blanks are maintained at ±0.05 mm).
Cutting Edge Straightness:≤0.02 mm per 25mm length.
Edge Geometry:R0.2–R0.4 with a -5° to -8° negative land bevel angle to reinforce the cutting edge and suppress cyclic micro-chipping.
Set Thickness Uniformity:Critical limit of ≤0.02 mm variance within a single 4-piece set. Uniform block thickness balances rotational cutting forces, eliminating rib-peeling eccentricity and protecting against oval thread profiles.
3. Complementary Workpiece Tolerances
Splicing Compliance: Thread profiles formed after rib peeling are engineered to support full structural compliance with JGJ107 and equivalent international reinforcement splicing standards regarding tensile and thread inspection parameters.
Post-Peeling Base Metal Diameter Tolerance: Maintained at an industry-standard ±0.2 mm dual tolerance on the stripped cylindrical surface, matching specific machine specifications to secure full thread depth during rolling.
Frequently Asked Questions (FAQ)
Q1: What are the distinct performance differences between W6 HSS and Cr12MoV/D2 peeling blades?
W6 HSS (M2): Delivers superior hot hardness (anti-softening up to 600°C) and higher structural impact toughness. It is preferred for heavy-duty, continuous line processing of high-strength HRB400/HRB500 rebar where the tool must withstand both constant cutting heat and impact shock without premature fracturing.
Cr12MoV (D2): Possesses extreme abrasive wear resistance due to its dense chromium-carbide hard phases. It is best suited for dry or heavily rusted bars where abrasive wear is the main failure mode and high-impact structural deflections are minimal.
Q2: Why do my peeling blades chip or break prematurely on site?
Premature tool failure on the shop floor is typically caused by:
Improper Blade Clearance: Incorrect running gaps between the upper/fixed cutting edges and the rebar base.
Loose Fastening Bolts: Micro-wobble under high-speed operation destroys the negative land bevel. Bolts must be torqued diagonally.
Inadequate Cooling: Running tools dry under high heat speeds up thermal fatigue. While M2 exhibits excellent hot hardness over mold steels, insufficient lubrication eventually triggers micro-cracking.
Q3: Why is the thickness uniformity within a 4-piece set controlled under ≤0.02 mm?
A single peeling head mounts a matched set of 4 pieces to shear the rebar circumference simultaneously. If thickness variance exceeds 0.02 mm, the cutting force unbalances, resulting in rib-peeling eccentricity. The resulting base metal cylinder becomes oval-shaped, causing the subsequent thread rolling dies to produce uneven, cross-threaded, or incomplete thread roots.
Q4: Can ALAS manufacture bespoke peeling inserts for obsolete or non-standard threading heads?
Yes. We provide 1:1 precise custom machining based on your CAD prints or physical used samples. Our workshop handles full internal CNC grinding and vacuum heat treatment to replicate special dimensions, hole layouts, or bevel angles within strict ±0.03 mm tolerances.
Q5: How often should an ALAS 4-sided reversible peeling blade be rotated?
Lifespan depends on lubrication flow, rebar hardness, and throughput volume. When the peeled steel surface exhibits prominent tearing burrs or the machine drive motor load rises abnormally, the cutting faces are passivated. Loosen the lock bolts, rotate each square block 90° to engage a fresh cutting edge, and recalibrate the running clearance.
Eliminate Thread Eccentricity – Get an Instant Factory Quote!
Frustrated by peeling eccentricity and cross-threaded roots breaking inspection standards? Upgrade your thread rolling lines with ALAS Machinery. Sold in precision-matched 4-piece installation sets, our 4-sided indexable peeling blocks maintain a critical thickness uniformity variance of ≤0.02 mm per set to ensure balanced cutting forces and perfect cylindrical base diameters. Select your factory grade: authentic W6/M2 HSS (HRC 62–65) with high thermal stability for continuous high-tensile HRB400/500 rebar, or D2/Cr12MoV (HRC 58–60) for high-abrasion rusted scaling bars. Accepting low MOQ orders from 20 pieces with 1:1 custom CAD blueprints supported. Request your direct factory-floor quotation within 12 hours.
Nanjing Alas International Co., Ltd. is a professional industrial tooling manufacturer focused on shear blades, bending dies, shredder blades, and custom wear parts. We offer full application engineering, material selection, setup guidance, and after-sales support to global customers. Tell us your requirements, and our engineering team will provide professional solutions for blade specification, tool life optimization, and cost-effective production.
