Products Description

We make SS Hex Head Bolts in two main grades: 304 and 316, both built to meet ASTM A193 standards. The 304 kind has 18-20% chromium and 8-10.5% nickel, while 316 steps things up with 2-3% molybdenum mixed in-that extra molybdenum is what makes it hold up better against rust. Both types are strong enough to handle 650-800 MPa of pull force; we've pushed them to 750 MPa in tests and they still didn't start to bend.

We put the 316 bolts through a tough 5% salt spray test (following ASTM B117 rules) and even after 1500 hours, there's not a spot of red rust. That's why they're a solid pick for places near the coast or in chemical plants where things get messy.

The hex head itself follows ASME B18.2.1 specs, and we can also make a 12-point version if you need it-it spreads out the twisting force better when you're tightening. The threads (UNC or UNF, per ASME B1.1) are a Class 2A fit, which means they're tight enough to stay put once fastened but still easy to screw in without fighting them. Wholesalers like the versatility: they work for everything from food processing equipment to marine hardware, reducing the need to stock multiple bolt types.

Factory Processing

We offer two finishes: passivated (ASTM A967) to form a 6-8μm protective layer, and bright polished (Ra 0.8μm max) for visible applications. The passivation process removes free iron, cutting corrosion risk by 40% compared to untreated bolts.

Our cold heading process ensures consistent head shape, with ±0.1mm tolerance on head height. Thread rolling (instead of cutting) increases fatigue strength by 30%, and we add thread-locking patches (per ASTM D3655) on request for permanent installations. Every bolt gets a go/no-go gauge check to ensure thread fit before shipping.

Production Strength

As a Chinese manufacturer with 10 years supplying EU and US industrial clients, we run 8 cold heading machines and 5 thread rollers, churning out 4,500 tons annually. Our raw wire comes from ISO 9001-certified mills, with each batch tested via OES to verify chemical composition (within 0.01% of ASTM specs).

Factory Commitments

Orders over 40 tons get a 5.5% discount, with 316 grade qualifying for an extra 0.5% off. We include free passivation on all orders.

Our guarantee: If any SS Hex Head Bolts fail to meet ASTM A193 tensile standards within 5 years, or show corrosion beyond 0.01mm/year in standard tests, we'll replace them within 6 days and cover all shipping costs. We also lock prices for 30 days, with a 3% discount for repeat orders placed within 90 days.

Product Parameters

Property	Details
Chemical Composition	Cr: 18-20%, Ni: 8-10.5%, Mo: 2-3%, Ti: 5×C–0.70% (titanium stabilizer), C: ≤0.08%, Mn: ≤2%, Si: ≤1%
Mechanical Strength	Tensile strength:650-800 MPa Yield strength: ≥205 MPa Hardness: ≤217 HB (Brinell) / ≤95 HRB (Rockwell)
Corrosion Resistance	Superior to 316 in high-temperature, chloride-rich, or acidic environments. Titanium eliminates intergranular corrosion (a common issue in 316 after welding). Resists pitting, crevice corrosion, and seawater exposure.
Temperature Range	Continuous service: -270°C to 870°C Suitable for both cryogenic and high-heat applications.
Magnetic Behavior	Non-magnetic in annealed condition (ideal for sensitive electronic environments).

Dimensional Specifications (Metric & Imperial)

316Ti hex bolts adhere to global standards for thread pitch, head dimensions, and length, ensuring compatibility with industrial systems.

Metric Size (M)	Thread Pitch (mm)	Hex Head Width (mm)	Hex Head Height (mm)	Length Range (mm)	Imperial Equivalent	Thread Type (Imperial)
M4	0.7	6.7	3.2	8-100	1/8"	UNC (1/8"-40), UNF (1/8"-48)
M5	0.8	8.0	4.5	10-150	5/32"	-
M6	1.0	10.0	5.2	12-200	3/16"	UNC (3/16"-24), UNF (3/16"-32)
M8	1.25	13.0	6.8	16-300	5/16"	UNC (5/16"-18), UNF (5/16"-24)
M10	1.5	16.0	8.4	20-400	3/8"	UNC (3/8"-16), UNF (3/8"-24)
M12	1.75	18.0	10.8	25-500	1/2"	UNC (1/2"-13), UNF (1/2"-20)

Standards & Compliance

316Ti hex bolts are manufactured to strict industry standards, ensuring consistency and reliability:

Standard	Scope
ISO 4017	Defines metric hex bolt dimensions, thread tolerances, and head geometry.
ASME B18.2.1	Governs imperial hex bolt specifications for industrial use.
DIN 933	Specifies full-threaded hex bolts (metric) with precise dimensional tolerances.
EN 10269	Covers fasteners for high-temperature service (relevant for 316Ti's heat resistance).

Key Advantages Over 316 and 304

316Ti's titanium stabilization gives it unique benefits compared to common stainless steels:

Feature	316Ti	316	304
Weldability	Excellent (no post-weld annealing needed).	Good (may require annealing to prevent corrosion).	Good, but limited in high-chloride environments.
High-Temp Performance	Superior (up to 870°C).	Good (up to 815°C).	Moderate (up to 870°C, but poor corrosion resistance).
Intergranular Corrosion	Resistant (titanium stabilizes carbides).	Vulnerable after welding.	Vulnerable after welding.
Cost	Higher (due to titanium addition).	Moderate.	Lower.

Typical Applications

316Ti hex bolts excel in demanding environments where corrosion resistance and high-temperature stability are critical:

Chemical processing: Pipes, reactors, and tanks handling acids (e.g., sulfuric, nitric).
Marine/offshore: Shipbuilding, oil rigs, and desalination plants (resists seawater).
Pharmaceutical machinery: Sanitary systems requiring corrosion resistance and easy cleaning.
Nuclear industry: Auxiliary equipment (tolerates radiation and high heat).
Heat exchangers: High-temperature fluid handling systems.