Low Carbon Steel Bolts Machining Service CNC Custom Parts

Material & Grade Options

You get stable, low-cost bolt performance with our low carbon / mild steel machining service. We stock and machine all common global equivalents, so you can source to your local standard without redesign.

Common Low Carbon Steel Grades We Machine

Standard	Grade	Typical Use Case
SAE / AISI	1008, 1010	Small cold-headed bolts, nuts, formed parts
SAE / AISI	1018, 1022	Hex bolts, carriage bolts, threaded specials
EN / ISO	C10C	General-purpose mild steel fasteners
China GB	Q235B	Structural bolts, anchor bolts
EN	S275JR	Structural and machinery bolts
ASTM	A36	Anchor bolts, base plate bolts, heavy hardware
SAE J403	Equivalents	Custom spec per drawing and material call-out

We cross-reference SAE J403, GB, EN, and ASTM grades in-house to meet your drawing and local code.

Typical Mechanical Properties (Reference)

Values below are indicative ranges for low carbon steels in bolt applications (as-rolled / normalized, non-alloyed). Final properties depend on diameter, process, and heat treatment.

Grade (Typical)	Strength Class Target	Tensile Strength (MPa)	Yield Strength (MPa)	Elongation A5 (%)	Hardness (HB)
SAE 1008 / 1010	4.6	330–420	200–260	28–35	90–120
SAE 1018	4.8 / 5.6	400–550	240–320	22–30	110–140
SAE 1022	4.8 / 5.6 / 8.8*	420–800*	260–640*	14–28	110–230*
Q235B / C10C	4.6 / 4.8	370–490	235–300	23–30	100–140
S275JR / A36	4.8 / 5.6	410–560	250–350	20–26	110–150

*With appropriate heat treatment (quench + temper), 1022 and similar can reach Class 8.8 requirement.

• We design material + process to match your required strength class (4.6 / 4.8 / 5.6 / 8.8).
• Full 3.1 material certificates issued with chemistry and mechanical test data on request.

Manufacturing Processes We Master for Low Carbon Steel Bolts

We focus on the most efficient and stable ways to produce custom low carbon steel bolts, from simple mild steel hex bolts to complex precision parts.

Cold Heading + CNC Secondary Machining

For most custom low carbon steel bolts—especially hex bolts, flange bolts, carriage bolts, and structural fasteners—we use:

• Cold heading for the bolt head and basic shape
• CNC secondary machining for faces, chamfers, grooves, drilled holes, and special details

This route is:

• Most cost-effective for medium to high volumes
• Ideal for SAE 1018 bolt manufacturing, Q235 bolt machining, and Grade 4.8 / 5.6 fasteners
• Stable in quality with tight dimensional control

We combine cold forging with our broader manufacturing process capabilities to keep both cost and lead time under control.

Full CNC Turning & Milling

When your design goes beyond standard shapes, we switch to full CNC machining:

• CNC turning for precision turned steel bolts, shoulder bolts, and long shank parts
• CNC milling for eye bolts, T-head bolts, square head bolts, and other non-standard heads

This process is best for:

• Low to medium quantities
• Complex geometry and custom threaded mild steel fasteners
• Tight tolerances and special fits that cold heading can’t achieve

Thread Rolling vs Cut Threading

We offer both thread rolling and cut threading for low carbon steel bolts:

• Thread rolling
  • Forms the thread by cold deformation
  • Better fatigue strength and smoother surface
  • Faster and more economical for standard metric, UNC, UNF threads
  • Ideal for cold forged low carbon fasteners
• Cut threading
  • Threads are machined by cutting
  • Flexible for short runs, prototypes, and special thread profiles
  • Suitable for large diameters and custom pitches

We’ll choose the most suitable method based on material, size, strength class, and your annual usage.

In-House Heat Treatment & Surface Finishing

To control performance and appearance from end to end, we handle:

• Heat treatment for strength adjustment and stress relief of mild steel bolts
• Surface finishing and coatings such as zinc, black oxide, and phosphating, supported by our dedicated surface treatment services

Keeping these processes in-house helps us:

• Maintain consistent quality
• Offer short, predictable lead times
• Support OEM customers needing stable, repeatable low carbon steel bolt machining service

Bolt Types & Head Styles for Low Carbon Steel Bolts Machining Service

For our Low Carbon Steel Bolts Machining Service, we support a full range of bolt types and head styles so you can match function, strength class, and cost in one place:

• Hex bolts / hex cap screws
  The most common choice for steel structures, machinery, and automotive. We cold head or fully machine hex heads with across-flat tolerances kept tight for reliable wrench engagement.
• Flange bolts
  Integrated washer face to spread load and speed up assembly. Ideal for engine, chassis, and structural joints where vibration resistance matters. Often supplied as zinc plated low carbon bolts for corrosion protection.
• Carriage bolts (round head, square neck)
  Smooth dome head with anti-rotation square neck under the head. Perfect for wood‑to‑steel joints, trailer beds, and construction where a clean visible surface is needed. We offer mild steel carriage bolts OEM with rolled or cut threads.
• Square head bolts
  Classic style for heavy industry, clamps, and refurbishment projects. The larger contact surface makes them easy to tighten in tight spaces and harsh environments.
• Eye bolts
  Fully machined or forged eyes for lifting, guiding, or anchoring. We control internal eye diameter and shank straightness for safe load handling with precision turned steel bolts.
• T-head bolts
  Designed to slide into T-slots and channels. Common in solar frames, assembly lines, and structural systems where adjustment is required after installation.
• U-bolts
  Formed and machined for pipe supports, axle clamps, and structural bracing. We hold leg spacing and thread length tight so nuts run smoothly and cl

Size & Thread Capabilities for Low Carbon Steel Bolts Machining Service

With our Low Carbon Steel Bolts Machining Service, we cover the most common and the most demanding sizes global customers ask for:

• Bolt diameter: from M4 – M48 or #10 – 2 inch, ideal for everything from small brackets to heavy structural connections.
• Bolt length: up to 600 mm, suitable for anchor bolts, foundation bolts, and long custom studs.
• Thread types:
  • Metric coarse / fine (e.g. M10×1.5, M16×2.0)
  • UNC / UNF for US and North American standards
  • BSW and other legacy inch threads for replacement parts
  • Custom threads for OEM designs and special fastener systems
• Machining tolerance: up to ±0.02 mm on critical dimensions for tight-fit and precision assembly.

Whether you need custom threaded mild steel fasteners for an OEM project or standard CNC machined mild steel bolts for repeat production, we hold size and thread consistency batch after batch, making your assembly work faster, safer, and more predictable.

Surface Treatment & Coating for Low Carbon Steel Bolts

For our Low Carbon Steel Bolts Machining Service, we control all key surface treatments in-house to hit your corrosion and torque targets with repeatable quality.

Main Coating Options

Coating / Treatment	Appearance	Typical Use Case	Corrosion Resistance*
Zinc plating Cr³⁺	Bright / blue/clear	General industrial, RoHS compliant	★★–★★★
Zinc plating Cr⁶⁺	Yellow / iridescent	Legacy specs where still permitted	★★★
HDG (Hot-dip galvanized)	Thick grey matt	Structural, outdoor, anchor bolts, wind & solar	★★★★
Geomet	Silver / grey	Automotive, structural, no hydrogen embrittlement	★★★★
Dacromet	Silver / grey	Heavy corrosion, brake / chassis parts	★★★★
Black oxide	Black matt	Indoor, aesthetic, low friction with oil	★★
Phosphating + oil	Dark grey / black	Assembly bolts, anti-galling, paint base	★★
Nylon patch	Colored patch on thread	Prevailing torque, anti-loosening	– (functional)
Wax / lubricant	Transparent	Stable torque, anti-seize on high-friction threads	– (functional)

*Relative rating for typical environments.

How We Match Coating to Your Application

• Outdoor / structural: we usually suggest HDG, Geomet or Dacromet for low carbon structural bolts and anchor bolts.
• Automotive / trailer: Geomet / Dacromet + wax gives strong corrosion resistance with stable tightening torque.
• General engineering: Zn plating (Cr³⁺) or phosphating + oil works well for most CNC machined mild steel bolts.
• Anti-loosening: add a nylon patch or post-applied locking element on custom threaded mild steel fasteners.

All coatings are validated by salt spray testing on request, and we follow typical automotive and industrial specs used by our IATF 16949 bolt manufacturing customers in sectors like mining and marine engineering, similar to our work for demanding marine engineering components.

Tell us your environment (indoor, coastal, buried in concrete, etc.) and we’ll recommend the most cost-effective coating stack for your low carbon steel bolts.

Quality Assurance for Low Carbon Steel Bolts Machining Service

We run strict quality control on every custom low carbon steel bolt we machine. From raw bar to final packing, each step is measured, recorded, and traceable.

100% Inspection on Critical Features

For all CNC machined mild steel bolts and cold forged low carbon fasteners, we carry out:

• 100% thread gauging (GO / NO-GO gauges) for metric, UNC, UNF, BSW, and custom threads
• Dimensional inspection on head size, shank, shoulder, and overall length
• Statistical sampling for non-critical dimensions to keep both quality and cost in balance

Our inspection team uses calibrated micrometers, calipers, ring/plug gauges, and optical measuring tools to ensure every Q235 bolt, A36 anchor bolt, or SAE 1018 bolt meets spec.

Full Material Traceability & Certifications

All low carbon steel grades (1008, 1010, 1018, 1022, Q235B, etc.) are purchased with heat numbers and full traceability. On request we provide:

• EN 10204 3.1 Material Test Certificates (3.1 MTC)
• RoHS and REACH compliance statements for coatings like zinc plating, black oxide, phosphating, and Geomet/Dacromet
• PPAP Level 3 documentation for automotive, trailer, and IATF 16949 projects

If you need deeper process visibility or want to audit our system, you can review our capabilities on our dedicated manufacturing services page.

Advanced Measurement & Corrosion Testing

For high-spec custom low carbon steel bolts and structural fasteners, we can supply additional reports:

• CMM inspection reports for tight tolerances down to ±0.02 mm on precision turned steel bolts
• Salt spray test reports (neutral salt spray) for zinc plated low carbon bolts, HDG, Geomet, and Dacromet-coated parts, according to your required hours

All reports are shared in clear PDF format so your quality team can plug them directly into your own PPAP or project documentation.

Industries & Typical Applications for Low Carbon Steel Bolts

Our low carbon steel bolts machining service is built for high-volume, real-world use. We focus on consistent quality, tight tolerances, and coatings that survive tough environments.

Construction & Scaffolding

We supply A36, Q235, S275JR and 4.6 / 4.8 structural bolts for:

• Scaffolding joints and couplers
• Formwork systems and temporary structures
• Building frames, handrails, and walkways

Smooth threads, reliable zinc or HDG coatings, and strong but ductile material make assembly faster and safer on site.

Automotive & Trailer

We produce CNC machined mild steel bolts for:

• Trailer chassis and tow hitches
• Suspension brackets and axle fixtures
• Body mounting and light commercial vehicles

For automotive and related sectors we follow strict process control and inspection similar to our precision machining services for industrial components.

Agricultural Machinery

Our custom low carbon steel bolts are widely used in:

• Harvesters, planters, and spreaders
• Frames, guards, and wear part mounting
• Implement hitch systems and brackets

Tough coatings like HDG, Geomet, and Dacromet help parts survive mud, fertilizer, and outdoor storage.

Renewable Energy (Wind Tower & Foundation)

We machine large-size flange and anchor bolts (e.g. M20–M48) for:

• Wind tower base rings
• Foundation and anchor systems
• Nacelle and platform structures

Stable quality, 100% thread gauging, and full traceability support long-term wind projects in Europe, North America, and Asia.

General Engineering & OEM

We support a wide range of OEM low carbon fasteners for:

• Machinery frames and equipment skids
• Conveyors, material handling systems
• General fabrication and steel structures

From short runs of custom machined bolts to repeat orders of standard hex and flange bolts, we keep quality stable and lead times predictable for global customers.

Why Choose Vastmaterial for Low Carbon Steel Bolts Machining Service

I run Vastmaterial to be a straight‑forward, reliable low carbon steel bolt supplier for global buyers who care about both cost and consistency.

Production Capacity That Scales With You

We combine cold heading and CNC machining under one roof:

Capability	Vastmaterial Setup	What You Get
CNC machining centers	50+ multi-axis CNC centers	Stable capacity for complex/custom bolts
Cold heading / cold forging lines	30+ production lines	Very competitive cost on standard fasteners
Process coverage	From raw bar/wire to finished packed bolts	One supplier, full traceability

One-Stop Low Carbon Steel Bolt Manufacturing

We keep the full process in-house as much as possible:

• Material sourcing (1008, 1018, Q235, A36, etc.)
• Cold heading + CNC secondary machining
• Thread rolling, heat treatment, surface coating
• Sorting, packing, palletizing and export documents

You deal with one team from RFQ to shipment. If you want to learn more about how we run our operation, you can check our background on the Vastmaterial company page.

Flexible MOQ for Custom & Machined Specials

We know not every project is a million-piece order:

• MOQ from 500 pcs for CNC machined specials and non-standard bolts
• Ideal for:
  • New project validation
  • Spare parts programs
  • Local distributors testing new SKUs

Fast & Predictable Lead Time

For most custom low carbon steel bolts:

• Typical lead time: 18–28 days after order confirmation
• Time covers tooling, production, basic inspection, and standard export packing
• Urgent projects: we can pull capacity forward if material is ready

Proven Supplier for Global Customers

Since 2009, we’ve supplied custom mild steel bolts and fasteners to customers across Europe, North America, and Asia:

Track Record	Numbers
Years in fastener manufacturing	15+ years
Global clients served	400+ OEMs, distributors, and EPCs
Typical cooperation model	Long-term contracts & repeat orders

Low carbon steel bolt market forecast:

If you’re ready to move from trial to stable supply, you can reach us directly via our main site at Vastmaterial – custom metal parts & fasteners.

Technical Resources for Low Carbon Steel Bolts Machining Service

I keep all the key data for low carbon steel bolts machining service in simple, ready-to-use formats. You don’t need to dig through standards; you can download and use these right away in your daily work.

Low Carbon Steel Bolt Grade Comparison (PDF)

You can request a compact PDF that compares the most common low carbon bolt grades I supply and machine:

Steel Grade	Standard	Typical Strength Class	Typical Use
1008/1010	SAE J403	4.6 / 4.8	Small hex bolts, screws, light duty
1018/1022	SAE J403	4.8 / 5.6	Structural bolts, carriage bolts
Q235B	GB/T 700	4.6 / 4.8	Construction bolts, plates
S275JR	EN 10025	4.6 / 4.8	Structural & anchor bolts
A36	ASTM A36	4.6 / 4.8	Anchor bolts, base plate bolts

This PDF helps you:

• Cross-check metric vs SAE vs Chinese vs EU grades
• Pick the right grade for strength, weldability and cost
• Match your spec to our machining and cold heading capabilities

Torque–Preload Reference Table

To avoid over-tightening or under-tightening, I offer torque guidance for CNC machined mild steel bolts in common sizes and coatings.

Size / Thread	Strength Class	Condition	Recommended Torque (Nm)
M10 × 1.5	4.8	Zinc plated, oiled	35–40
M12 × 1.75	4.8	Black oxide	60–70
M16 × 2.0	4.8	Plain, oiled	150–170
1/2″-13 UNC	Grade 2 / 4.6	Zinc plated	70–80

Use this table as a starting point; I can also adapt values to your:

• Application (static / dynamic / structural)
• Surface finish (zinc, HDG, phosphated, waxed, etc.)
• Lubrication and assembly method

Plating Thickness & Corrosion Resistance Chart

For zinc plated low carbon bolts, HDG anchor bolts, and other coated fasteners, I share a quick chart that links coating thickness to typical salt spray hours (neutral salt spray, NSS).

Coating Type	Typical Thickness (µm)	Approx. NSS Hours to Red Rust*
Zinc Cr+3, clear	8–12	120–240
Zinc Cr+3, thick layer	12–20	240–480
Geomet / Dacromet	8–12	480–1000
HDG (hot dip galvanized)	40–80	600–1500
Phosphate + oil	5–10	24–72

*Values are typical ranges; I can provide actual salt spray test reports for your project.

If you need any of these technical sheets (PDFs, tables, or charts) for your custom low carbon steel bolts, I’ll send clean, ready-to-use files you can drop straight into your design pack, PPAP, or quality docs.

Customer Reviews & Case Studies – Low Carbon Steel Bolts Machining Service

European Wind Project – 120,000 pcs M20×110 Flange Bolts

For a European wind energy customer, we supplied 120,000 pcs M20×110 low carbon steel flange bolts, cold headed and CNC machined from Q235 / S275JR / SAE 1018 equivalents.

• Strength class: 4.8, with full 3.1 MTC and salt spray test reports
• Process: cold forging + secondary CNC + thread rolling + zinc plating
• Result: 0 claims, on‑time delivery in 3 partial shipments, all bolts passed on‑site fit-up and torque tests for wind tower flange connections.

Long-Term Contract – 800,000 pcs Grade 4.8 Hex Bolts

We support an OEM customer with an annual contract for 800,000 pcs Grade 4.8 low carbon steel hex bolts in mixed sizes.

• Materials: 1008 / 1010 / 1018 mild steel, optimized per size for best cost
• Processes: cold heading + machining + bulk zinc plating, automatic sorting, 100% thread gauging
• Benefits for the client:
  • Stable quality for automotive and trailer parts
  • Lead time locked by schedule – monthly releases, no stock-out
  • Cost-down program through tooling optimization and high-volume production

Real photos of production, packaging, and installed bolts are available on request to help you verify our low carbon steel bolts machining service capability before you place your first order.

FAQ – Low Carbon Steel Bolts Machining Service

Difference between low carbon and medium carbon bolts?

Low carbon (mild steel) bolts

• Typical materials: 1008, 1010, 1018, Q235, C10C, A36
• Strength classes: 4.6, 4.8, 5.6 (sometimes 8.8 after heat treat)
• Features:
  • Easier to cold form, machine, and weld
  • Higher ductility, better for shock and bending
  • Lower material cost

Medium carbon bolts

• Typical materials: 1045, 35#, 40Cr (after heat treat)
• Strength classes: 8.8, 10.9, 12.9
• Features:
  • Higher tensile and yield strength
  • Lower elongation, less forgiving in overload
  • More demanding heat treatment and process control

Type	Typical Grade	Strength Class	Main Use
Low carbon	1008 / 1018 / Q235	4.6 / 4.8 / 5.6	General, construction, light structure
Medium carbon	1045 / 35# / 40Cr	8.8 / 10.9+	High-load, automotive, machinery

If you’re not sure which way to go, send us your drawing and application, and I’ll recommend the most cost-effective option.

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When to choose cold-headed + machining vs full CNC?

Cold heading + secondary machining – best for volume

• Ideal for: hex bolts, flange bolts, carriage bolts, standard studs
• MOQ: usually from 5,000–10,000 pcs per size
• Benefits:
  • Lowest cost per piece
  • High speed, stable quality
  • Good use of low carbon steels like 1018, Q235

Full CNC machining – best for specials

• Ideal for: short runs, complex heads, shoulder bolts, eye bolts, custom threads
• MOQ: we start from 500 pcs for specials
• Benefits:
  • Maximum flexibility on geometry
  • Tight tolerances (up to ±0.02 mm)
  • Fast prototype and trial orders

Quick guide:

Requirement	Best Process
Standard hex / flange bolt	Cold heading + machining
Large yearly volume	Cold heading + machining
Complex or non-standard	Full CNC turning & milling
Small batch / trial build	Full CNC machining

You can send us both your annual volume and first order quantity; I’ll help pick the right route.

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Can you supply strength class 4.6 / 4.8 / 5.6 / 8.8 in low carbon?

Yes. For low carbon steel bolts machining service, we regularly supply:

Strength Class	Typical Material	Process Route
4.6	Q235, 1008, 1010	Cold heading + thread rolling, no heat treatment
4.8	Q235B, 1018, C10C	Cold heading + controlled rolling, optional normalizing
5.6	1018, 1022	Cold heading + machining, light heat treatment
8.8 (low carbon alloy / boron steel)	10B21, 15B21, 1022M	Cold heading + quench & temper + thread rolling

• We test tensile, yield, hardness, and elongation per ISO 898-1 / SAE J429.
• Full 3.1 material certificate, mechanical test report, and PPAP Level 3 are available on request.

If you need a specific strength class plus coating (e.g., zinc plated 4.8 hex bolts or HDG 8.8 anchor bolts), tell me your standard and working conditions, and I’ll match the right material + process for you.

Ready for a Quote on Low Carbon Steel Bolts?

Send me your drawing or sample details, and I’ll come back to you with a clear price and lead time within 4 hours.

• What you can send: 2D/3D files (PDF, STEP, DWG), photos, or a sketch with key dimensions
• What you’ll get:
  • Best process choice (cold heading + machining or full CNC)
  • Optimized cost for your quantity and material grade
  • Confirmed delivery time and packing solution

Upload your file, tell me your material, quantity, and surface finish, and let’s get your custom low carbon steel bolts machining service started today.