A4-70不锈钢六角螺栓工厂
XZ Fastener supplies A4-70 stainless steel hex bolts for industrial buyers who need dependable corrosion resistance, clear specifications, and export-ready packing. These external hex fasteners are commonly ordered as DIN 933 full thread hex bolts, ISO 4017 metric hex head bolts, DIN 931 partial thread bolts, or drawing-based parts according to project requirements. A4-70 is suitable for many marine, outdoor, chemical equipment, and machinery assemblies where 316-family stainless steel is preferred over carbon steel. Buyers can source 不锈钢六角螺栓 with size lists, material documents, matching nuts and washers, and inspection details confirmed before production.
标准型
DIN 933 / ISO 4017 全螺纹； DIN 931 / ISO 4014 可选
实力
A4-70, with A4-80 available upon request
材质
A4 / 316-系列奥氏体不锈钢
完成
普通、钝化、酸洗钝化、润滑
应用
Marine fittings, outdoor structures, equipment, chemical plants
买家在采购 A4-70 不锈钢六角螺栓之前应了解什么
A4-70 hex bolts are often selected for corrosion resistance first and strength second. If the joint is highly loaded, exposed to vibration, or controlled by a structural standard, the bolt grade, nut grade, washer hardness, tightening method, and service environment should be checked together before purchase.
Confirm the standard first
DIN 933 and ISO 4017 indicate full thread hex bolts, while DIN 931 and ISO 4014 indicate partial thread hex bolts. XZ Fastener also supplies A2 和 A4 六角头螺栓 for projects that require mixed full thread and partial thread lists.
Separate material from strength
A4 describes the stainless steel group, while 70 describes the property class. A4-70 is different from Grade 8.8 carbon steel hex bolts; the correct choice depends on corrosion exposure, joint load, and the mating material.
Check thread fit and galling risk
Stainless steel threads can gall under high assembly speed or dry tightening. For repeated assembly, buyers may request lubrication, anti-seize guidance, or a matching nut and washer set.
常见采购说明
Clear purchasing descriptions reduce confirmation time and help avoid mixed standards in the same order. Typical buyer wording includes:
- A4-70 stainless steel hex bolts DIN 933 full thread, M8 x 30, plain finish.
- 316 stainless steel metric hex head bolts ISO 4017, A4-70, passivated.
- DIN 931 partial thread A4-70 hex bolts with matching stainless nuts and flat washers.
- Stainless steel hex cap screws M6-M24, A4-70, for marine equipment assembly.
- DIN 933 全螺纹六角螺栓 in carbon steel when the buyer specifies zinc plated DIN 933 bolts, black oxide DIN 933 bolts, hot dip galvanized DIN 933 bolts, or Grade 8.8 carbon steel hex bolts instead of stainless steel.
If the order combines stainless and carbon steel items, mark each line clearly with material, grade, finish, and inspection requirement.
详细规格表
| 项目 | 规格 | 买家须知 |
|---|---|---|
| 产品名称 | A4-70 不锈钢六角螺栓 | Can be supplied as bolts only or with matching nuts and washers. |
| 标准 | DIN 933、ISO 4017、DIN 931、ISO 4014、基于图纸的零件 | Confirm full thread or partial thread before quotation. |
| 直径范围 | Common metric sizes such as M3-M36; larger sizes by order requirement | Actual range depends on standard, length, and production method. |
| 长度 | 标准长度或根据图纸定制长度 | For thread details, see this 螺栓螺纹长度指南. |
| 线程 | 公制粗牙螺纹；可根据要求提供细间距 | Provide pitch if the order is not standard coarse thread. |
| 材质 | A4 / 316-系列奥氏体不锈钢 | 最终化学成分遵循所选标准和采购订单。 |
| 属性等级 | ISO 3506参考下的A4-70 | A4-80 can be discussed when higher stainless strength is needed. |
| 表面光洁度 | 普通、钝化、酸洗钝化、抛光、润滑 | 表面处理应与腐蚀暴露和组装方法相匹配。 |
| 检查 | Dimensions, thread gauges, visual appearance, material documents, mechanical test reports upon request | 生产开始前注明检验文件。 |
| 包装 | Bulk cartons, small boxes, pallet packing, labels, barcodes, private packing | Packaging can be arranged according to order requirement. |
材质及牌号说明
A4 stainless steel is a molybdenum-bearing austenitic stainless group widely used where chloride exposure, outdoor moisture, or chemical environments may attack ordinary carbon steel or lower stainless grades. A4-70 indicates a stainless property class commonly associated with a minimum tensile strength level of 700 MPa under ISO 3506 reference conditions.
For many buyers, the most important comparison is A2 versus A4. A2 is suitable for general indoor and mild outdoor applications, while A4 is typically preferred for marine air, chemical equipment, wastewater facilities, and coastal structures. For more material selection background, review XZ Fastener’s guide to A2 与 A4 不锈钢紧固件.
A4-70 should not be treated as a direct substitute for Grade 8.8 carbon steel hex bolts without checking load requirements. Grade 8.8 carbon steel has higher strength, while A4-70 offers better corrosion resistance in many environments.
Inspection requirements can be confirmed before production, including dimensions, thread fit, surface condition, and documents.
表面处理选择指南
Most A4-70 stainless steel hex bolts are ordered in plain stainless or passivated finish. Passivation helps remove free iron from the surface and supports the natural stainless protective layer. Pickling and passivation may be requested when welding scale, heavy oxide, or stronger surface cleaning is required.
| 完成 | When to Use | Important Note |
|---|---|---|
| 普通不锈钢 | General machinery, indoor assemblies, clean stainless appearance | Economical and widely used for standard stainless fasteners. |
| 钝化 | Outdoor, marine air, chemical equipment, food-related support frames | Common choice when corrosion resistance and clean surface are both important. |
| 酸洗和钝化 | More demanding surface cleaning requirements | Confirm appearance expectations and inspection method in advance. |
| Lubricated or anti-seize prepared | 存在反复拧紧或磨损问题的组件 | 使用润滑时扭矩值可能会发生变化。 |
| 碳钢涂料 | 镀锌DIN 933 螺栓，黑色氧化DIN 933 螺栓，热镀锌DIN 933 螺栓 | These are generally carbon steel alternatives, not standard A4 stainless finishes. |
For coating comparisons on carbon steel and other fasteners, see this 紧固件精加工指南.
制造和质量控制
Production planning starts from the confirmed standard, size list, material grade, thread type, finish, packaging, and document requirements. Depending on diameter and length, A4-70 stainless steel hex bolts can be produced by cold heading, hot forging, machining, thread rolling, or thread cutting. The selected process depends on size, quantity, tolerance, and lead time.
生产前
XZ Fastener checks the purchase description, drawing, material requirement, thread pitch, finish, packing method, and inspection documents. For non-standard items, 定制紧固件 can be reviewed from drawings or samples.
生产过程中
Common control points include head dimensions, across-flat size, thread length, thread gauge fit, surface appearance, burr control, and mixing prevention between stainless grades.
发货前
Carton labels, pallet marks, quantity, finish, and inspection documents are checked according to order requirement. Material test certificates and third-party inspection can be discussed before order confirmation.
应用领域
A4-70 stainless steel hex bolts are selected when buyers need a balance of corrosion resistance, standard metric dimensions, and practical assembly with wrenches or sockets. They are widely used in:
- 海洋设备和沿海设施
- 化学加工设备
- 户外钢铝组件
- 废水处理系统
- 泵、阀门和管道支撑硬件
- 食品和饮料支撑结构
- 太阳能安装和裸露设备框架
- Machinery maintenance and replacement parts
For submerged seawater, strong chloride chemicals, or critical load-bearing joints, confirm the engineering requirement before selecting A4-70.
如何获得更快的报价
A clear inquiry helps XZ Fastener quote the correct A4-70 stainless steel hex bolts without repeated clarification. Please provide:
- Size list, such as M8 x 30, M10 x 50, M12 x 80.
- 标准，例如DIN 933、ISO 4017、DIN 931、ISO 4014 或图纸编号。
- 材质和牌号，例如 A4-70、A4-80、A2-70 或 316 不锈钢。
- 表面处理要求，例如普通、钝化、酸洗钝化或润滑。
- Quantity for each size and whether partial shipment is acceptable.
- Packaging requirement, including bulk carton, small box, pallet, label, barcode, or private brand packing.
- Inspection requirements, such as MTC, dimensional report, salt spray reference, or third-party inspection.
- Destination port or delivery term if freight support is needed.
对于结构化查询，请使用 请求报价 page and attach drawings or a spreadsheet if available.
常问问题
Is A4-70 the same as 316 stainless steel?
A4 is commonly associated with the 316-family stainless steel group, while A4-70 also defines a mechanical property class. The final chemical composition and mechanical values should follow the selected standard and purchase order.
DIN 933 和DIN 931 六角螺栓有什么区别？
DIN 933 usually refers to full thread hex bolts, while DIN 931 usually refers to partial thread hex bolts. Buyers should confirm thread length because it affects assembly, shear area, and stock availability.
Can A4-70 stainless steel hex bolts replace Grade 8.8 carbon steel hex bolts?
Not automatically. A4-70 is chosen for corrosion resistance, while Grade 8.8 carbon steel hex bolts are chosen for higher strength. The joint load, environment, and engineering requirement should be checked before substitution.
Which finish is recommended for A4-70 stainless bolts?
Plain stainless and passivated finishes are common. Passivation is often requested for outdoor, marine air, chemical equipment, and clean stainless assemblies. Lubrication may be useful when galling risk is a concern.
XZ Fastener可以提供配套的螺母和垫圈吗？
Yes. Matching stainless hex nuts, flat washers, spring washers, and packing sets can be supplied according to the bolt material, thread, standard, and project requirement.
What documents can be requested with the shipment?
Buyers may request material test certificates, dimensional inspection reports, visual inspection records, packing lists, and other documents according to order requirement. Document needs should be stated before production.
Can custom sizes or non-standard hex bolts be produced?
Custom lengths, special thread pitch, drawing-based head dimensions, markings, and packaging can be discussed. Send drawings, samples, photos, quantity, and application details for review.
Send Your A4-70 Stainless Hex Bolt Inquiry
To receive a practical quotation, send your size list, finish, quantity, packaging method, and inspection requirements. Include the standard or drawing number, destination, and whether matching nuts and washers are needed. XZ Fastener will review the details and help confirm a supply plan according to your order requirement.
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