A metric fastener size chart helps procurement and engineering teams speak the same language. It reduces wrong RFQs, wrong thread matching, and last-minute assembly problems.

In metric fasteners, size is usually written as M + nominal diameter × pitch × length. For example, M12 × 1.75 × 80 means a 12 mm nominal diameter, 1.75 mm thread pitch, and 80 mm length.

For buyers, the key is not only the “M size.” Pitch, length, grade, coating, and matching nuts or washers must also be confirmed.

Basic Metric Fastener Size Chart

Common Metric Sizes and Coarse Pitches

This chart is a starting point. Final selection should follow the drawing, project standard, or equipment manual.

For common catalog items, review 标准紧固件 and confirm whether the product follows DIN, ISO, ASTM, or a project drawing.

What Procurement Teams Should Confirm

仅有尺寸是不够的

A purchase request that says “M12 bolt” is incomplete. It can still lead to the wrong product.

确认：

• Product type: bolt, screw, nut, washer, stud, or anchor
• 直径和长度
• Thread pitch: coarse or fine
• Thread length: full thread or partial thread
• Grade: 4.8, 8.8, 10.9, 12.9, A2-70, etc.
• Surface finish: plain, zinc, HDG, zinc flake, black, stainless
• 配套螺母和垫圈

For bolt sourcing, review 螺栓产品。对于垫圈匹配，请检查 洗涤产品.

Engineering Checks Before Approval

Match the Size to the Application

Engineering teams should consider load, vibration, corrosion, installation space, and maintenance frequency.

For load-bearing assemblies, 高强度紧固件 may be required. For outdoor, marine, or humid environments, compare 各种涂层紧固件 or stainless options.

If the part has special head shape, long thread, shoulder diameter, or non-standard length, use 定制非标紧固件 and provide a drawing.

最终建议

A metric fastener size chart is useful, but it should not replace a complete specification. Good purchasing data includes size, pitch, length, standard, grade, coating, matching parts, and application condition.

对于更广泛的采购，请查看完整的 紧固件产品 range before finalizing the RFQ.