DIN933 DIN931 Black Oxide Carbon Steel Hex Bolts Grade 4.8 6.8

These hex head bolts are manufactured from carbon steel and designed for reliable fastening in industrial, construction, and machinery applications. The hex head shape allows easy tightening with common wrench and socket tools, making the bolts suitable for production assembly, repair work, and project installation.

The main listed grades are 4.8 and 6.8, suitable for general and medium‑duty fastening applications. For buyers with higher strength requirements, the available grade range can include 4.8, 6.8, 8.8, 10.9, and 12.9. This makes the product suitable for different load levels, from standard equipment assembly to stronger structural fastening.

The product title highlights black oxide hex bolts in M10x80, M12x90, M14x100, and M16x110 sizes. The full size range can cover M8‑M72, allowing buyers to source multiple diameters and lengths from one product series. Surface treatment options include plain, black, zinc plated, and HDG, so the bolts can be matched to indoor assembly, machinery use, or outdoor corrosion protection needs.

Specification Table

Key Features

• Carbon steel material for stable fastening strength and economical bulk purchasing.
• DIN933 and DIN931 standards for common hex bolt applications.
• Main grade options include 4.8 and 6.8, with wider grade choices up to 12.9.
• M10x80, M12x90, M14x100, and M16x110 sizes for machinery and structural use.
• Black, plain, zinc plated, and HDG surface options for different working environments.
• Nuts can be supplied for complete bolt‑and‑nut fastening sets.
• M8‑M72 size range supports wholesale stock and project procurement.
• Packaging can be arranged as small pack, carton, and pallet for export orders.

Material and Grade Explanation

Carbon steel is widely used for hex bolts because it offers dependable strength, efficient production, and cost‑effective purchasing for large‑volume orders. Grade 4.8 bolts are suitable for general fastening and light to medium‑duty assembly. Grade 6.8 bolts provide stronger performance for industrial equipment, metal frames, and construction hardware.

For projects requiring higher tensile strength, grade 8.8, 10.9, and 12.9 options can be selected according to the load requirement, installation torque, working environment, and mating components. Choosing the correct grade helps improve fastening reliability and service life.

Surface Treatment Options

Black finish is commonly used for machinery, equipment, and applications where a dark surface appearance is preferred. Zinc plated finish offers a clean metallic look and general corrosion protection. Plain finish is suitable for indoor use or further surface processing. HDG finish is available for outdoor or more corrosion‑prone applications where stronger rust resistance is required.

Applications

These DIN933 and DIN931 carbon steel hex bolts are suitable for machinery assembly, equipment maintenance, steel structures, warehouse frames, pipe supports, construction hardware, agricultural machinery, metal brackets, industrial production lines, and general fastening work.

They are suitable for buyers who need multiple sizes and grades in one bolt family. The M8‑M72 range supports standard inventory replenishment, engineering projects, wholesale distribution, and customized fastener orders.

Packaging and Supply

The bolts can be supplied in small packs, cartons, and pallets for easy storage, handling, and export shipment. Packaging can be adjusted according to order quantity, destination market, and buyer requirements. Bulk supply is available for distributors, contractors, machinery factories, and construction fastener channels.

FAQ

Q1: What material are these bolts made from?

A1: They are made from carbon steel.

Q2: What are the main grades?

A2: The main listed grades are 4.8 and 6.8. Other available grade options include 8.8, 10.9, and 12.9.

Q3: What sizes are listed for this product?

A3: The listed sizes include M10x80, M12x90, M14x100, and M16x110. The available size range can cover M8‑M72.

Q4: What surface treatments are available?

A4: Available surface treatments include black, plain, zinc plated, and HDG.

Q5: What standards can the bolts follow?

A5: DIN933 and DIN931 are the main listed standards. DIN, ASME, GB, JIS, and ISO options can also be supplied.

Q6: Are nuts included?

A6: Nuts can be supplied, and the listed configuration includes two nuts.

Q7: Can the bolts be customized?

A7: Yes. Custom size, grade, surface treatment, packaging, drawings, and samples can be discussed for bulk orders.

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Send your required size, grade, finish, quantity, and packaging request to get a fast quotation.

Hotop Fasteners can supply DIN933 and DIN931 carbon steel hex bolts for machinery, construction, steel structure, wholesale, and export fastening projects.