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Stainless Steel Hex Bar
| MOQ: | 5ton |
| Price: | Based on grade, size, surface, processing, quantity and current raw material market price. |
| Standard Packaging: | Standard seaworthy export packing with bundles, waterproof wrapping, pallets or wooden cases. |
| Delivery Period: | 7-15 |
| Payment Method: | L/C,D/A,Western Union,T/T,D/P |
| Supply Capacity: | Stock supply, regular production and custom manufacturing available. |
Shaanxi Shangyou Stainless Steel Co., Ltd. supplies stainless steel hex bar for nuts, bolts, valve components, hydraulic fittings, couplings and automatic-machined parts. Hex bar is ordered by the distance across flats, not by the corner-to-corner diameter. Cold-drawn and bright conditions are commonly selected to reduce machining time and improve consistency in repetitive production.
| Purchase Item | Supply Information |
|---|---|
| Grades | 303, 304/304L, 316/316L, 410, 416, 17-4PH |
| Across Flats | 5–100 mm typical; inch sizes by order |
| Length | 3 m, 6 m, 12 ft, 20 ft or fixed blanks |
| Condition | Hot rolled for larger sizes; cold drawn or bright for precision machining |
| Tolerance | Across-flats and twist tolerance to ordered standard or drawing |
| Surface | Black, pickled, cold drawn, bright or polished |
| Standards | ASTM A276, A582, A564; EN 10088-3 |
| Testing | Across flats, twist, straightness, PMI and hardness |
| Processing | Cold sawing, chamfering, threading, drilling and CNC machining |
| Documents | MTC 3.1 with heat-number traceability |
Grade 303 is widely used for screw-machine parts because sulfur improves chip breaking and tool life. However, it has lower resistance to pitting and poorer weldability than 304 or 316L. Grade 304 offers a balanced general-purpose choice, while 316L is preferred when molybdenum-enhanced pitting resistance and good weldability are important. 17-4PH hex bar can provide much higher strength after aging for demanding fasteners, shafts and valve parts.
Purchasers should specify the across-flats size, length, corner geometry, twist, straightness, surface and dimensional tolerance. For finished nuts or fittings, the drawing should identify thread class, machining allowance and whether the hex flats remain visible. ASTM A582 is appropriate for free-machining grades; ASTM A276 covers common general-purpose grades; ASTM A564 applies to age-hardening grades.
Cold sawing provides consistent blanks for automatic lathes. Additional services include end chamfering, center drilling, turning, threading and rough CNC machining. Austenitic grades should be machined with sharp tools, rigid support and adequate feed. For small 303 components, chip control is generally easier. 17-4PH may be rough-machined in solution-treated Condition A, aged, and then finish-ground or threaded according to the drawing.
A high-machinability grade is not automatically the best service grade. 303 should not be selected only to reduce machining cost when the part will be welded, exposed to seawater or used in high-pressure containment. Threaded components also require evaluation of galling, preload, lubrication, temperature and dissimilar-metal contact.
| Grade / Designation | Key Chemistry (wt.%) | Density g/cm³ | Tensile MPa | Yield MPa | Elong. % | Hardness | Heat Treatment / Condition |
|---|---|---|---|---|---|---|---|
| 303 / S30300 / 1.4305 | C≤0.15; Cr 17–19; Ni 8–10; S≥0.15 | 7.83 | Heat/size dependent | Heat/size dependent | Per order | Approx. 160 HB annealed | Annealed; cannot be hardened by heat treatment |
| 304 / S30400 / 1.4301 | C≤0.08; Cr 18–20; Ni 8–10.5 | 7.93 | ≥515 | ≥205 | ≥40 | ≤201 HB | Solution annealed; not hardenable by heat treatment |
| 316L / S31603 / 1.4404 | C≤0.03; Cr 16–18; Ni 10–14; Mo 2–3 | 8.00 | ≥485 | ≥170 | ≥40 | ≤217 HB | Solution annealed; rapid cooling after hot work |
| 17-4PH H900 / S17400 / 1.4542 | C≤0.07; Cr 15–17.5; Ni 3–5; Cu 3–5; Nb+Ta 0.15–0.45 | 7.75 | ≥1310 | ≥1170 | ≥10 | Approx. 40 HRC or higher | Solution treated, then aged at 482°C for H900 |
Values are representative engineering references for common conditions. The applicable ASTM/EN standard, section size, ordered condition and MTC control acceptance. Grade 303 is frequently hardness-controlled under ASTM A582, so tensile values should not be assumed without the certified heat data.
| Process / Inspection | Purpose | Ordering Note |
|---|---|---|
| Saw cutting / cold sawing | Fixed lengths and production blanks | State length tolerance, squareness and burr requirement |
| Peeling / turning | Remove hot-worked surface and improve diameter | State final raw size and machining allowance |
| Centerless grinding | Control diameter, roundness and surface | State ISO tolerance, straightness and Ra separately |
| Chamfering / facing | Improve loading, assembly and length control | Provide angle, width, radius or finished length |
| PMI / chemistry verification | Confirm alloy family and heat identity | XRF does not independently confirm L-grade carbon |
| Hardness / mechanical tests | Verify condition and grade requirements | Test method, sampling and condition must match the standard |
| UT / third-party inspection | Evaluate internal quality and witness compliance | Define method, acceptance class, coverage and report |
- Nuts, bolts and threaded parts
- Valve and pump fittings
- Hydraulic couplings
- Automatic screw-machine products
- Instrumentation components
- High-strength fasteners
Send across-flats size, grade, length, tolerance, quantity and final part drawing. Include thread, corrosion and heat-treatment requirements for machined fasteners or fittings.
Request a Quote · Send Your Size List · Upload Drawing or MTO · Confirm Grade and Condition
Hex bar is normally specified by the distance across opposite flats. Corner-to-corner diameter is larger and should not be used as the purchasing size unless clearly stated.
Its sulfur addition improves chip breaking and machining speed, which is useful for high-volume nuts, fittings and screw-machine parts.
No. 303 generally has lower pitting resistance because of sulfur-bearing inclusions. 304 or 316L is preferred when corrosion performance is more important than maximum machinability.
Yes, within available size ranges. Cold drawing improves surface and size consistency but may increase strength and residual stress.
Yes. Common imperial across-flats sizes can be supplied or produced. Metric and inch requirements should not be mixed in the same tolerance statement.
Twist describes rotation of the flats along the bar length. The allowable value depends on size, condition and standard and should be stated when automatic feeding or visible flats are critical.
Yes. One-end or two-end chamfering, facing and center drilling can be arranged.
Yes. Condition A and several aged conditions are possible. The exact condition affects strength, toughness, hardness and machining response.
Across-flats measurement, straightness, twist, PMI and hardness are common. Additional mechanical or UT requirements depend on the final part.
Long bars are bundled and protected from moisture. Short precision blanks can be layered in wooden cases with labels preserving heat-number traceability.
