Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175 / ISO 15156-2
- NORSOK M-650 Qualified
- API 6A Certified
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Super Duplex 2507 Hex Bar, UNS S32750
Super Duplex 2507 hex bar in UNS S32750 (EN 1.4410) is the preferred blank stock for hex nuts, hex couplings, instrument fittings and short hex-headed parts where machining-from-round would waste 30 percent of the bar mass. TorqBolt holds 2507 hex bar from 8 mm to 65 mm across flats at the Mumbai warehouse, cold-drawn to ASTM A484 tolerance, with EN 10204 Type 3.1 certificates and Type 3.2 on request.
Hex bar is supplied to ASTM A479 for stainless steel bar in pressure-vessel service and ASTM A276 for shapes. Companion stud bar and round are supplied from the same heat lots, allowing matched-set certificates on bolt-and-nut assemblies. Sour-service certification per NACE MR0175 / ISO 15156-3 is available.
Super Duplex 2507 Hex Bar Size Range
| Across Flats | ASME B18.2.2 Nut Size | Length |
|---|---|---|
| 8 mm | M5 | 3.0 to 4.0 m |
| 13 mm | M8 / 5/16" | 3.0 to 4.0 m |
| 17 mm | M10 | 3.0 to 4.0 m |
| 19 mm | M12 / 1/2" | 3.0 to 4.0 m |
| 24 mm | M16 / 5/8" | 3.0 to 4.0 m |
| 30 mm | M20 / 3/4" | 3.0 to 4.0 m |
| 36 mm | M24 / 7/8" | 3.0 to 4.0 m |
| 46 mm | M30 / 1-1/8" | 3.0 to 4.0 m |
| 55 mm | M36 / 1-3/8" | 3.0 to 4.0 m |
| 65 mm | M42 / 1-5/8" | 3.0 to 4.0 m |
Super Duplex 2507 Hex Bar Chemistry
Per ASTM A479 designation S32750: 25Cr-7Ni-3.5Mo-0.3N. Copper is restricted to 0.50 max as residual, not intentional. PREN of 41 or higher.
| Element | Min % | Max % |
|---|---|---|
| Carbon | (no min) | 0.030 |
| Chromium | 24.0 | 26.0 |
| Nickel | 6.0 | 8.0 |
| Molybdenum | 3.0 | 5.0 |
| Nitrogen | 0.24 | 0.32 |
| Copper | (no min) | 0.50 max, residual, not intentional |
Super Duplex 2507 Hex Bar Mechanical Properties
| Property | Minimum | Test Standard |
|---|---|---|
| Tensile strength | 800 MPa (116 ksi) | ASTM A370 |
| Yield strength | 550 MPa (80 ksi) | ASTM A370 |
| Elongation in 50 mm | 15 percent | ASTM A370 |
| Hardness | 32 HRC max bar, 28 HRC max NACE | NACE MR0175 |
| Charpy V-notch at minus 46 C | 45 J min | NORSOK M-630 |
Machining Hex Bar Into Nuts
- CNC bar-feed lathes drill, chamfer and tap nut blanks in a single setup. Threading uses tap holders with full lead-angle inserts.
- Speeds 30 to 50 percent of austenitic 316L. Sharp inserts, positive rake and flood coolant prevent work-hardening at the cut edge.
- Roll-tap on small sizes (M5 to M12) for higher productivity; cut-tap on M16 and larger to control torque.
- Across-flats tolerance per ASTM A484: minus 0.13 to plus 0.13 mm typical for cold-drawn 2507 hex.
Super Duplex 2507 Hex Bar Applications
- Hex nut blanks per ASTM A194 grade 7A
- Heavy hex nut blanks for stud bolt assemblies
- Hex couplings and adapter fittings for instrument tubing
- Hex-head plugs and pipe fittings, machined and threaded
- Short hex-headed bolts and screws below stock-bolt sizes
Related Products and Standards
- Super Duplex 2507 round bar for stud bolts
- Super Duplex 2507 square bar
- Super Duplex 2507 cold finished bar
- Super Duplex 2507 hex nuts
- Super Duplex 2507 fasteners
- ASTM A479 reference
Super Duplex 2507 Hex Bar FAQ
Which sizes are stocked as hex bar?
8, 13, 17, 19, 24, 30, 36, 46, 55 and 65 mm across flats are routine. Other sizes are produced from round bar by drawing or grinding to order.
Why use hex bar instead of round for nuts?
Round-to-hex machining wastes about 30 percent of bar mass as chips. Cold-drawn hex is sized close to the across-flats dimension already, so the lathe only chamfers, drills and threads. On 2507 the chip cost is amplified by tool wear from the high yield strength.
What tolerance does TorqBolt deliver on 2507 hex?
Across flats: minus 0.13 to plus 0.13 mm on common sizes per ASTM A484. Tighter tolerances (h9 / h10) are available on request for sizes up to 36 mm. Length tolerance is plus or minus 25 mm random.
Can 2507 hex bar be supplied with NACE certification?
Yes, NACE MR0175 / ISO 15156-3 compliance with 28 HRC max hardness and 35 to 65 percent ferrite is available on request. Heat-treatment, hardness and ferrite-count records are stated on the EN 10204 Type 3.1 or 3.2 certificate.
Does 2507 hex bar contain copper?
No, copper is not an intentional alloying element. ASTM A479 permits 0.50 max as residual, not intentional. Copper-bearing super duplex (Zeron 100 S32760, Ferralium 255 S32550) is a different alloy and supplied separately.
Can I order matched hex and round from the same heat?
Yes. TorqBolt routinely supplies matched-heat hex bar (for nut blanks) and round bar (for stud bolts) so that bolt-and-nut assemblies carry a single heat number on the EN 10204 Type 3.1 certificate, simplifying QA traceability for project owners.
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