carbon steel flange bolts wholesale supplier
XZ Fastener supplies carbon steel flange bolts for distributors, OEM assembly lines, equipment builders, and project procurement teams that need repeatable dimensions, stable mechanical performance, and practical packing for bulk orders. As a carbon steel flange bolts wholesale supplier, we support metric flange head bolts in common strength classes such as 8.8 and 10.9, with finishes selected according to installation environment. The integrated washer face helps distribute load and simplify assembly where separate washers are not preferred. Sizes, thread length, serrated or non-serrated flange options, carton labels, pallet packing, and inspection documents can be arranged according to order requirement.
Quick Specs
What Buyers Should Know Before Sourcing Carbon Steel Flange Bolts
Confirm the flange style
Carbon steel flange bolts may use a serrated flange for improved resistance to loosening, or a smooth flange when the mating surface must be protected. Before placing a wholesale order, confirm whether the assembly allows serration marks, whether a washer is still required, and whether the head style must match DIN 6921, ISO 4162 or an existing sample. For broader product matching, XZ Fastener also provides related flange bolts and nuts for industrial assemblies.
Check strength, coating and packaging together
Strength class, surface finish and packing method should be reviewed as one purchasing package. Class 8.8 and 10.9 flange bolts usually require controlled heat treatment, while outdoor or humid environments may require zinc, zinc-nickel, hot dip galvanizing, Dacromet or another finish. Bulk buyers can also compare adjacent fastener products when an order includes bolts, nuts, washers and custom parts in one shipment.
Common Purchasing Descriptions
To reduce clarification time, purchasing teams usually describe flange bolts with size, standard, strength class, surface finish, flange type and packing. Typical descriptions include:
- DIN 6921 hex flange bolts, carbon steel, class 8.8, zinc plated, serrated flange.
- ISO 4162 metric flange bolts, class 10.9, black oxide, full thread or partial thread.
- Carbon steel flange head bolts, non-serrated flange, plain oiled finish, bulk carton packing.
- Wholesale flange bolts with barcode labels, neutral cartons, palletized export packing and inspection report.
- Mixed bolt order including DIN 933 full thread hex bolts, Grade 8.8 carbon steel hex bolts and metric hex head bolts.
- Related hex bolt order with zinc plated DIN 933 bolts, black oxide DIN 933 bolts and hot dip galvanized DIN 933 bolts.
For drawings, non-standard dimensions or special head marking, XZ Fastener can review custom fasteners according to sample or technical drawing.
Detailed Specifications Table
| Предмет | Available Specification | Buyer Notes |
|---|---|---|
| Product type | Hex flange bolts, serrated flange bolts, non-serrated flange bolts | Select serration based on mating surface and vibration requirement. |
| Стандарт | DIN 6921, ISO 4162, EN, IFI, ANSI or customer drawing | Send the required standard or sample photo when dimensions are critical. |
| Diameter range | Common metric sizes such as M5 to M24; other sizes available upon request | Large diameters may require different forming or machining routes. |
| Length range | Short, medium and long lengths according to order requirement | Confirm whether length is measured under head according to the selected standard. |
| Thread | Full thread, partial thread, coarse thread or fine thread | Provide pitch if the order is not standard coarse metric thread. |
| Материал | Low carbon steel, medium carbon steel or alloy steel | Material is selected according to required strength class and heat treatment. |
| Strength class | 4.8, 5.8, 8.8, 10.9, 12.9 | Class 8.8 and above normally require controlled heat treatment and testing. |
| Finish | Plain, zinc plated, yellow zinc, black oxide, phosphate, HDG, Dacromet, Geomet | Finish should match corrosion exposure, assembly friction and appearance needs. |
| Packing | Bulk cartons, small boxes, bags, pallet packing or customized labels | Wholesale packing can be arranged according to distributor or project requirement. |
| Inspection | Dimension, thread gauge, hardness, tensile, proof load and coating checks | Inspection items can be confirmed before production and shipment. |
Material and Grade Explanation
Carbon steel flange bolts are selected when buyers need strength, cost control and broad availability. Low carbon steel is often used for lower strength classes, while medium carbon steel or alloy steel is used for higher strength classes after heat treatment. Grade 8.8 is a common choice for machinery and steel frame assemblies, while 10.9 may be selected when the joint requires higher tensile strength and clamping force.
The meaning of bolt grades should be checked before substitution. A higher grade is not automatically suitable for every assembly because torque, mating nut grade, coating, hydrogen embrittlement risk and application load must be reviewed. For grade comparison, see XZ Fastener’s buyer guide on what 8.8 means on a bolt.
Surface Finish Selection Guide
| Finish | Typical Use | Purchasing Consideration |
|---|---|---|
| Plain or oiled | Indoor assembly, temporary protection, further processing | Lower corrosion resistance; packing moisture control is important. |
| Zinc plated | General machinery, indoor equipment and light-duty protection | Common for wholesale orders where appearance and cost matter. |
| Чернение | Machinery appearance, indoor equipment and low-reflection assemblies | Usually requires oiling; not recommended as the only protection outdoors. |
| Phosphate | Automotive and mechanical assemblies with controlled friction needs | Often combined with oil; torque behavior should be confirmed. |
| Hot dip galvanized | Outdoor structures, utility projects and exposed environments | Thread allowance and nut compatibility should be checked before ordering. |
| Dacromet or Geomet | Higher corrosion resistance without thick zinc buildup | Available upon request when project specifications require it. |
For mixed orders that include flange bolts and hex bolts, this fastener coating guide can help compare zinc, hot dip galvanized, Dacromet, PTFE and other coating choices.
Manufacturing and Quality Control
Carbon steel flange bolts are typically produced through cold heading for common sizes, with hot forging or machining used for larger or special parts. The process may include wire preparation, heading, thread rolling, heat treatment, surface finishing, sorting and packing. For wholesale supply, stable thread quality and consistent head geometry are especially important because bolts must run smoothly in repeated assembly operations.
Quality control may include dimensional inspection, thread gauge checking, hardness testing, tensile or proof load testing, coating thickness checking and visual sorting. If the order includes special markings, coating requirements, salt spray expectations or third-party inspection, these details should be confirmed before production.
Приложения
Carbon steel flange bolts are widely used where the integrated flange can spread load, reduce separate washer handling and improve assembly efficiency. Typical applications include:
- Automotive brackets, chassis components, engine covers and equipment housings.
- Agricultural machinery, trailers, construction machines and maintenance repair kits.
- Steel frames, guardrails, conveyor systems, racking and industrial platforms.
- HVAC equipment, pump assemblies, compressor bases and machinery panels.
- OEM production lines that require repeatable carton labels, lot tracking and pallet packing.
When the purchasing list includes several bolt families, this article on bolt types explained can help separate flange bolts, hex bolts, carriage bolts and other commonly requested fasteners.
How to Get a Faster Quotation
A clear inquiry helps XZ Fastener check availability, production route, packing cost and inspection needs quickly. For wholesale flange bolt orders, please include:
- Size list with diameter, length, thread pitch and quantity for each item.
- Required standard such as DIN 6921, ISO 4162, IFI or drawing-based dimensions.
- Strength class such as 4.8, 8.8, 10.9 or 12.9.
- Finish requirement, including color, coating thickness or salt spray expectation if applicable.
- Flange type: serrated or non-serrated.
- Packing method: bulk carton, small box, bag, private label, pallet or export packing.
- Inspection documents, test reports, photos before shipment or third-party inspection requirements.
Buyers can request a quote with drawings, samples or an Excel size list. For urgent projects, please also contact XZ Fastener with the required delivery schedule and destination country.
Часто задаваемые вопросы
Can XZ Fastener supply carbon steel flange bolts in wholesale cartons?
Yes. Carbon steel flange bolts can be supplied in bulk cartons, small boxes, bags, pallet packing or customized label packing according to order requirement.
What is the difference between serrated and non-serrated flange bolts?
Serrated flange bolts can improve resistance to loosening on suitable mating surfaces, while non-serrated flange bolts are preferred when surface marking should be reduced or controlled.
Which strength class is commonly used for carbon steel flange bolts?
Class 8.8 is common for machinery and steel frame assemblies. Class 10.9 or 12.9 may be used when higher strength is required, but torque, mating parts and coating should be reviewed together.
Can flange bolts be supplied with zinc plating or hot dip galvanizing?
Yes. Zinc plated, yellow zinc, black oxide, phosphate, hot dip galvanized, Dacromet and Geomet finishes can be discussed according to corrosion environment and project specification.
What information is needed for a fast quotation?
Please send the size list, standard, strength class, finish, quantity, packing method, destination and inspection requirements. Drawings or sample photos are useful for non-standard parts.
Can I combine flange bolts with other fasteners in one order?
Yes. Orders can be discussed together with hex bolts, nuts, washers, carriage bolts, threaded rods and custom fasteners when the size list and packing requirements are clear.
Send Your Wholesale Flange Bolt Inquiry
For a practical quotation, send XZ Fastener your size list, finish, quantity, packaging plan and inspection requirements. Please include the standard, strength class, flange type, carton label needs and destination port when available.
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