C1038 Cold Heading Quality Steel Wire

C1038 is a medium-high carbon steel positioned between standard carbon grades (C1018, C1022) and alloy steels (4037, 4140). With carbon content of 0.35–0.42%, C1038 delivers significantly higher strength than the lower-carbon grades while remaining cold-headable in spheroidize-annealed condition.

It bridges a real gap in the CHQ buyer’s toolkit: applications that need more strength than C1022 can deliver but where the cost or chemistry of an alloy steel isn’t justified. C1038 also responds to heat treatment, making it useful for medium-strength quenched-and-tempered parts where 4037’s hardenability isn’t needed.

Nevers and Company stocks C1038 in coil form from major US CHQ mills with A2LA-accredited labs. USA melted and processed, with full chemistry verification on every coil.

Chemistry (AISI / SAE 1038)

Element	Min	Max
Carbon (C)	0.35	0.42
Manganese (Mn)	0.60	0.90
Phosphorus (P)	—	0.040
Sulfur (S)	—	0.050

All values in weight percent. Heat analysis per AISI/SAE standards.

Typical Mechanical Properties

As-drawn (cold-headed condition, spheroidize-annealed feed):

Property	Typical Value
Tensile strength	90,000 – 115,000 PSI
Yield strength	75,000 – 95,000 PSI
Reduction of area	40 – 50%
Elongation in 2 in.	10 – 16%

Quenched & tempered (typical medium-strength heat treatment):

Property	Typical Value
Tensile strength	130,000 – 160,000 PSI
Yield strength	110,000 – 140,000 PSI
Core hardness	HRC 28 – 35

Final heat-treated properties depend on tempering temperature and section size.

Common Applications

• Strength-critical fasteners — bolts, studs, and machine screws where C1022 strength is insufficient but alloy cost isn’t justified
• Medium-strength heat-treated parts — quenched and tempered hardware for sections where through-hardenability isn’t critical
• Shafts, pins, and axles — components needing wear resistance and moderate strength
• Wrenches and hand tools — cold-headed and heat-treated tool components
• Agricultural and equipment hardware — plow bolts, hitch pins, and other parts requiring strength and toughness

When to Specify C1038

Choose C1038 when:

• Your part needs more strength than C1022 delivers as-headed
• Heat treatment is acceptable but the application doesn’t require alloy steel
• Cost or specification rules out 4037 or 4140
• The part geometry permits less aggressive cold heading (C1038 work-hardens faster than lower-carbon grades)

For higher strength or larger sections requiring consistent through-hardness, 4037 is the better choice. For lower strength with better formability, step down to C1022.

Available Sizes

Nevers stocks C1038 in diameters from 0.135” to 0.500” (3.43 mm – 12.70 mm). Common stocked sizes include:

• 0.175” – 0.255” for small strength-critical hardware
• 0.285” – 0.375” for medium machine bolts
• 0.410” – 0.500” for heavier components

Available Conditions

Nevers stocks C1038 in two spheroidize-annealed conditions, both with phosphate-and-lubricant (P&L) coating applied as standard for cold heading:

• SAFS (Spheroidized Annealed at Finish Size) — our default. Annealing is the final processing step before coating, producing the softest, most ductile condition with the lowest internal stress. Choose SAFS for severe upsetting, deep extrusion, and demanding cold-heading where maximum formability matters.

• SAIP (Spheroidized Annealed In Process) — adds $2/cwt over SAFS. Annealing is followed by a light final cold draw (6–9% reduction) that sets tighter dimensional tolerances and produces a bright drawn finish. Choose SAIP for high-speed automated headers where consistent diameter and smooth feed behavior matter more than maximum formability.

See Cold Heading Wire Finishes: SAFS vs SAIP for a detailed comparison.

C1038 should generally not be cold-headed in as-drawn or as-rolled condition — spheroidize-annealed feed stock is strongly preferred to avoid cracking and excessive tool wear.

Quality Assurance

Medium-high carbon CHQ wire requires tighter chemistry control and more careful processing than low-carbon grades. Inclusion content and microstructure significantly affect cold-heading performance. Nevers sources C1038 only from mills with proven medium-carbon CHQ practice, and verifies chemistry on every incoming heat.

Frequently Asked Questions

What is C1038 used for? C1038 is a medium-high carbon CHQ steel used for strength-critical fasteners and machine parts — bolts, studs, shafts, pins, and heat-treated hardware where higher strength is required than C1022 can deliver but alloy steel isn’t justified by the application or budget.

Can C1038 be cold-headed? Yes, but it requires spheroidize-annealed feed stock and careful tooling. C1038 work-hardens faster than lower-carbon grades, and as-drawn or as-rolled material will typically crack in heading. Multi-blow operations and intermediate annealing are common for complex parts.

What’s the difference between C1038 and 4037? C1038 is a plain-carbon steel; 4037 is a molybdenum alloy steel. 4037 has deeper hardenability, better tempering resistance, and produces more consistent mechanical properties in heavy sections. C1038 is more cost-effective for medium-strength applications that don’t require alloy performance.

Can C1038 produce Grade 5 fasteners? With proper heat treatment, C1038 can meet Grade 5 properties in smaller sections, but 10B21 or C1022 are more common choices because their lower carbon content makes them easier to cold-head. C1038 is rarely the right choice specifically for Grade 5.

Is C1038 weldable? C1038 can be welded but requires preheat and post-weld heat treatment for most applications. The heat-affected zone hardens significantly and can crack without proper procedure control. Welding is uncommon in fastener applications.

Does Nevers stock C1038 in non-annealed condition? Standard stock is spheroidize-annealed for cold heading. As-rolled and normalized conditions are available on mill order for applications where the parts won’t be cold-formed (machining, hot forging, etc.).