Product Name
Mechanical Parts Square Steel (Square Bar for Precision Mechanical Parts)
Introduction
Mechanical Parts Square Steel are solid square-section steel bars produced as blanks or semi-finished stock for machined mechanical components - shafts with flats, coupling hubs, keys, heavy pins, bush housings, jig & fixture blocks and other precision parts. Supplied in hot-rolled, cold-drawn or precision-ground conditions, square bars offer easy clamping, predictable machining allowances and good dimensional control for repeatable manufacturing.
Typical Materials & Grades
Carbon steels: C15 / C22 / C45 (general purpose).
Alloy steels: 1045, 4140 / 42CrMo (quenched & tempered possible).
Stainless: 304 / 316 / 17-4PH (corrosion resistance / precipitation hardening).
Tool & bearing steels: 52100, D2 for wear-critical parts.
Special alloys: nickel alloys, duplex stainless on request.
Supply Conditions & Finishes
Hot-rolled: economical for large sizes; typical surface scale.
Cold-drawn / bright: tighter across-flats tolerances, better straightness and surface finish.
Precision ground / turned & ground: for bearing faces, tight assembly fits and minimal machining allowance.
As-forged or forged blanks: for large, near-net shapes.
Pre-treatments: annealed, normalized, quenched & tempered, induction/carburized surfaces per spec.
Typical Sizes & Tolerances
Across-flats range: commonly 6 mm → 300 mm (custom larger by forging).
Lengths: cut-to-length (100 mm → several metres); standard mill lengths 1–6 m.
Typical tolerances:
Hot-rolled: ±0.2 – ±2.0 mm (size dependent).
Cold-drawn: ±0.02 – ±0.3 mm.
Precision ground: ±0.005 – ±0.05 mm possible.
Straightness: typically ≤ 0.2 – 1.5 mm/m depending on process and size.
Weight Calculation (quick)
Mass per metre (steel, ρ ≈ 7850 kg/m³):
mass (kg/m) = (side in mm)² × 0.00785
Examples:
20 × 20 mm → 3.14 kg/m
50 × 50 mm → 19.63 kg/m
100 × 100 mm → 78.50 kg/m
Key Features & Advantages
Easy workholding: square faces simplify clamping, indexing and fixture design.
Tight dimensional control: cold-drawn and ground options minimize machining allowance and scrap.
Material & heat-treat flexibility: choose grades and tempering to meet strength, toughness and wear requirements.
Good machinability: annealed / pre-hardened conditions available to optimize cycle time.
Traceability: MTC and batch marking available for quality systems.
Typical Applications
Coupling hubs, flanged adapters and machine tool parts.
Shafts with flats, keys, large dowels and locking pins.
Guide rails, jigs, fixtures and gauge blocks.
Bearing housings, gearbox internals and heavy-duty fastener blanks.
Forging feedstock and near-net blanks for large components.
Value-Added Services
Cut-to-length, chamfering and end facing.
Precision turning, milling, drilling, keyways and broaching prior to shipment.
Centerless or OD grinding; surface grinding for flatness/parallelism.
Heat treatment (quench & temper, case hardening, nitriding) with hardness reports.
Hard chrome plating, black oxide, phosphate or corrosion coatings.
CNC profiling, slotting, tapping and assembly/kitting for production lines.
Quality Assurance & Testing
Mill Test Certificate (MTC): chemical and mechanical results with heat number traceability.
Dimensional inspection: across-flats, straightness and squareness checks; runout/flatness reports for ground bars.
Mechanical testing: tensile, yield, hardness and Charpy impact where required.
NDT: MT/UT/PT available for critical components.
Batch marking & traceability on request.
Packaging & Delivery
Bundled on timber skids with polymer spacers; precision pieces individually wrapped with end caps.
Oiled/VCI protection for long storage; crates for ground/finished components.
Handling & single-piece limits planned to transport/crane capacity.
Typical lead times: stock sizes short (days → 2 weeks); custom grades, grinding or heat treatment 2–8+ weeks depending on quantity.
Ordering Information - What We Need
Please provide:
Across-flats × length × quantity for each size.
Material grade and required supply condition (hot-rolled / cold-drawn / ground / heat-treated).
Tolerance class and straightness requirement.
Surface finish / coating and any machining/features required (keyways, holes, threads).
Testing/certification needs (MTC, hardness, NDT).
Transport/cranage constraints and desired delivery date.
If you send a size list and intended part use, I can return a size-to-weight table, recommend optimal grades/conditions for machining vs bearing use, and suggest machining allowances and heat-treatment paths.
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