40Cr high tensile bolts factory
XZ Fastener manufactures 40Cr high tensile bolts for buyers who need controlled alloy steel material, heat treatment, thread accuracy, surface finish, and export-ready packing. 40Cr is commonly selected for stronger metric hex head bolts, studs, and special bolting parts used in machinery, vehicle components, tooling, and steel structure assemblies. Products can be supplied according to DIN, ISO, GB, ANSI, or buyer drawings. Purchasing teams can review related fastener products and send size lists for factory quotation.
Quick Specs
What Buyers Should Know Before Sourcing 40Cr High Tensile Bolts
40Cr high tensile bolts are usually ordered when standard carbon steel bolts are not enough for load, tightening force, or fatigue conditions. Before sourcing, confirm the required standard, diameter, length, thread pitch, full or partial thread, heat treatment, property class, finish, packing, and inspection method.
For non-standard head dimensions, shoulder bolts, fine threads, extended lengths, drilled holes, or project-specific markings, XZ Fastener can review custom fasteners according to drawings, samples, or clear technical descriptions.
Common Purchasing Descriptions
- 40Cr high tensile hex bolts, quenched and tempered, black oxide finish.
- 40Cr metric hex head bolts, Grade 10.9, partial thread, packed by size and batch.
- DIN 933 full thread hex bolts in 40Cr alloy steel for machinery assembly.
- Grade 8.8 carbon steel hex bolts for applications where medium tensile strength is acceptable.
- Zinc plated DIN 933 bolts and black oxide DIN 933 bolts for equipment and workshop stock.
- Hot dip galvanized DIN 933 bolts for outdoor steel structures, with thread fit reviewed before production.
Detailed Specifications Table
| Item | Available Options | Factory Notes for Buyers |
|---|---|---|
| Product Type | Hex bolts, heavy hex bolts, flange bolts, studs, shoulder bolts, and special bolting parts | Send drawings for non-standard geometry, special head height, or controlled tolerance. |
| Material | 40Cr alloy steel; alternative alloy steel grades available upon request | Equivalent grades should be confirmed by chemical composition and mechanical properties. |
| Standard | DIN 931, DIN 933, ISO 4014, ISO 4017, GB, ANSI, ASTM, or buyer drawing | State the standard revision if the project specification controls it. |
| Diameter Range | Metric and inch bolt sizes can be reviewed according to order quantity and tooling | Large diameters may require additional review for heat treatment depth and straightness. |
| Thread | Metric coarse, metric fine, UNC, UNF, full thread, partial thread | Include pitch, tolerance, and mating nut requirement in the size list. |
| Heat Treatment | Quenching and tempering according to strength, hardness, or drawing requirement | Provide required property class, hardness range, tensile strength, or test method. |
| Surface Finish | Plain oil, black oxide, zinc plated, phosphate, Geomet, Dacromet, hot dip galvanized | Finish selection should match corrosion exposure, torque condition, and appearance needs. |
| Inspection | Dimensional check, thread gauge, hardness, tensile, proof load, coating thickness, visual inspection | Inspection reports or third-party checks should be confirmed before order placement. |
| Packing | Bulk cartons, small boxes, pallets, export labels, project labels, mixed-size packing | Provide carton weight limit, pallet rules, label format, and shipping mark if needed. |
Material and Grade Explanation
40Cr is a chromium alloy steel commonly used for mechanical parts and high tensile bolts after heat treatment. Compared with ordinary low carbon steel, 40Cr can offer improved hardenability and higher strength potential when quenching and tempering are properly controlled.
For international projects, 40Cr should not be treated as automatically interchangeable with another grade unless the drawing or buyer specification allows it. Buyers should confirm chemical composition, mechanical properties, hardness, tensile strength, proof load, and test method before production.
Surface Finish Selection Guide
- Plain oil: suitable for indoor storage or parts that will be assembled soon after delivery.
- Black oxide: common for machinery bolts where a dark appearance and light oil protection are acceptable.
- Zinc plated: used for general corrosion protection and clean appearance in dry environments.
- Phosphate: selected for controlled friction, oil retention, or specific assembly requirements.
- Geomet or Dacromet: considered when improved corrosion resistance is needed for high tensile bolts.
- Hot dip galvanized: used for outdoor steel structures, with coating thickness and thread fit reviewed in advance.
Manufacturing and Quality Control
Production Review
Factory production planning covers material confirmation, drawing review, heading or machining, thread rolling or cutting, heat treatment, surface finishing, inspection, batch separation, and packing. For 40Cr bolts, heat treatment control is a key step because it directly affects strength, hardness, and service performance.
For material traceability, buyers can discuss raw material inspection, batch control, and documentation before production starts.
Inspection Points
Common checks include size measurement, thread gauge inspection, head dimension verification, hardness test, tensile or proof load test when required, coating thickness, surface appearance, marking, quantity, and packing label review.
For more detail on process checks, review XZ Fastener’s article about manufacturing quality control.
Applications
Heavy Machinery
Used in frames, brackets, housings, lifting components, and equipment maintenance assemblies.
Automotive and Transport
Selected for mechanical assemblies where strength, thread engagement, and vibration resistance matter.
Mining Equipment
Applied in high-load fastening positions where impact and repeated maintenance cycles are considered.
Tooling Fixtures
Used in clamping systems, fixture plates, dies, molds, and workshop tooling assemblies.
Steel Structures
Can be reviewed for structural bolting packages where grade, finish, and inspection are controlled.
Industrial Maintenance
Supplied for replacement stock, repair kits, and multi-size maintenance fastener orders.
How to Get a Faster Quotation
A complete inquiry helps the factory check material, tooling, heat treatment, finish, inspection, packing, and delivery details without repeated clarification. For 40Cr high tensile bolts, strength class and heat treatment requirements should be listed clearly.
- Send size list with diameter, length, thread pitch, standard, and quantity.
- Confirm full thread or partial thread, property class, and material grade.
- Attach drawings for non-standard dimensions, special markings, holes, or controlled tolerances.
- State finish, packaging method, label format, carton weight, pallet requirement, and destination.
- List inspection requirements, reports, or third-party checking before quotation.
Factory Communication Checklist
For mixed orders, separate each bolt size and finish by line item. For replacement bolts, send photos, samples, or measurements if no drawing is available. If bolts will be assembled with nuts, washers, painted steel, or galvanized steel, mention the mating parts so thread fit and coating thickness can be reviewed.
To move quickly, contact the XZ Fastener team through the quote link above with your purchase file and target delivery requirement.
FAQ
Can XZ Fastener manufacture 40Cr high tensile bolts according to DIN or ISO standards?
Yes. 40Cr high tensile bolts can be reviewed according to DIN, ISO, GB, ANSI, ASTM, or buyer drawings. Please provide the standard, size, thread pitch, grade, finish, quantity, and inspection requirement.
What strength class can 40Cr bolts be supplied in?
40Cr bolts can be heat treated for high tensile applications, with classes such as 8.8 or 10.9 reviewed according to size, standard, and order requirement. Buyers should state the required property class or mechanical values.
Which finish is commonly used for 40Cr high tensile bolts?
Black oxide, zinc plating, phosphate, Geomet, Dacromet, and hot dip galvanizing can be discussed. The suitable finish depends on corrosion exposure, assembly torque, storage time, and appearance requirements.
Can 40Cr bolts be supplied with test reports?
Inspection reports for dimensions, hardness, tensile or proof load, coating thickness, and other agreed items can be discussed before order confirmation. Requirements should be stated in the inquiry.
Can XZ Fastener make non-standard 40Cr bolts from drawings?
Drawing-based bolts can be reviewed according to order requirement. Please provide dimensions, tolerances, material grade, heat treatment, finish, inspection requirements, and quantity.
What information is needed for a factory quotation?
Please send product standard or drawing, size list, thread pitch, material, strength class, finish, quantity, packaging, inspection requirements, and delivery destination.
Send Your 40Cr High Tensile Bolt Inquiry
For a faster quotation, send your size list, finish, quantity, packaging, and inspection requirements. Drawings, samples, mating nut details, destination, and document needs help XZ Fastener confirm production and factory supply arrangements more accurately.
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