Product Overview
Bright hexagonal bars are cold-drawn or centerless peeled precision steel profiles featuring exact across-flats dimensions and a clean, scale-free surface. Built for automated high-speed machining, these bars eliminate preliminary turning operations, reducing cycle times for fastener and hydraulic fitting production.
Technical Specifications
|
Parameter |
Specification Range |
|
Standard Grades |
AISI 1018, AISI 1045, AISI 4140, SUS 304, SUS 316 |
|
Size Range (Across Flats) |
6 mm to 80 mm (0.236 in to 3.15 in) |
|
Tolerance Class |
h9, h11 (ISO standard) |
|
Surface Finish |
Cold drawn bright, Ra <= 1.6 um, oil-coated for corrosion protection |
|
Straightness |
Max 0.5 mm / 1000 mm |
|
Standard Lengths |
3,000 mm, 6,000 mm, or custom cut-to-length |
|
Manufacturing Standards |
ASTM A29, EN 10278, JIS G4803 |
Product Advantages
Tight Dimensional Control:
Cold-drawn dies maintain strict across-flats tolerances, minimizing tool wear during automated multi-spindle lathe operations.
Optimized Surface Integrity:
Free of hot-rolled scale, decarburization layers, and surface cracks, reducing preparatory machining stock removal.
Enhanced Mechanical Properties:
Cold working increases tensile strength and yield strength compared to hot-rolled equivalents, improving final part structural performance.
Consistent Batch Uniformity:
Inline optical sorting and hardness testing ensure stable machinability across multi-ton production lots.
Applications
Fasteners: Standard and custom hex nuts, bolts, socket head cap screw components, and threaded studs.
Hydraulics & Pneumatics: Valve bodies, hose fittings, manifolds, and fluid connector components.
Hand & Power Tools: Wrenches, sockets, drive adapters, and screwdriver shafts.
Automotive Hardware: Steering components, fuel system connectors, and transmission pins.
Customization & Processing
Raw Material Sourcing -> Acid Pickling & Coating -> Multi-Pass Cold Drawing / Peeled -> Multi-Roll Straightening -> Inline Eddy Current Testing -> Automated Chamfering
Exact fixed-length sawing (-0/+5 mm) with deburred or chamfered ends utilizing automated high-speed cutting lines.
Annealed (Spheroidize annealed), Normalized, or Quenched & Tempered (Q&T) via in-house or partner controlled-atmosphere furnaces to hit specific hardness targets (e.g., 200-250 HB).
VCI paper wrapping, heavy-duty woven belt bundling, or export-grade wooden cases to prevent transit oxidation.
Quality Control & Inspection
Production lines operate under ISO 9001:2015 certified protocols. Every lot undergoes strict verification before dispatch:
Dimensional Verification: Micrometer and laser gauge inspection across flats and diagonal dimensions.
Metallurgical Analysis: Spectrometer chemical composition checks against ASTM/EN material standards.
Non-Destructive Testing (NDT): 100% inline electromagnetic eddy current testing for surface and subsurface defects.
Mechanical Testing: Tensile strength, yield strength, elongation, and Brinell/Rockwell hardness testing.
Third-Party Inspection: Support for independent verification by SGS, BV, or TUV prior to shipment.
Documentation: EN 10204 3.1 Mill Test Certificate (MTC) supplied with every shipment.
Packaging & Shipping
Bundling: Securely strapped with high-tensile steel bands, wrapped in anti-rust plastic film and moisture-resistant woven fabric.
Export Crating: Wooden box packaging available for port-to-port maritime shipping or heavy-duty overland transit.
Weight Limits: Standard export bundles restricted to 2,000 kg - 3,000 kg for safe container loading and overhead crane handling.
FAQ
Q: What is the standard manufacturing tolerance for your bright hexagonal bars?
A: Standard production adheres to ISO h11 or h9 tolerances. Tighter tolerances can be produced upon specific engineering review.
Q: Do you supply a Mill Test Certificate with the shipment?
A: Yes. Every delivery includes an EN 10204 3.1 MTC detailing chemical composition, heat numbers, and mechanical test results.
Q: What is the minimum order quantity (MOQ) for custom steel grades or non-standard sizes?
A: MOQ typically starts at 2 metric tons per size/grade for scheduled production runs. Stock items have flexible minimum limits.
Q: How are the bars protected against rust during ocean freight?
A: Bars receive an application of rust-preventative industrial oil, followed by an inner layer of moisture-barrier plastic film and an outer layer of woven textile wrapping.
Q: Can you supply cut-to-length hexagonal bars for direct CNC feeding?
A: Yes. Bars are cut to precise lengths with optional end chamfering to fit automatic bar feeders on CNC lathes.
Q: What non-destructive testing methods are used during production?
A: Inline electromagnetic eddy current testing inspects 100% of the bar length for surface laps, seams, and micro-cracks.
Request a Quote
Submit material grade, across-flats size, tolerance class, quantity, and destination port to receive a formal quotation within 24 hours.
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