Fastener Selection for Robotics机器人紧固件选型知识

Fasteners by position按部位选紧固件

A humanoid robot can be divided into five positions by load and structure. The table lists fasteners commonly used at each; sizes are typical supply ranges, not universal design recommendations.人形机器人按受力和结构可分为五个部位。下表列出各部位常用的紧固件；所列尺寸为可供应或常见规格范围，并非通用设计推荐值。

Five-step selection选型五步法

1. Joint and load. Robot joints may experience combined axial, transverse, bending, torsional and impact loads. Transverse slip at the clamped interface can lead to self-loosening, so first establish the required preload.确定连接与载荷。机器人关节可能承受轴向、横向、弯矩、扭矩及冲击复合载荷；连接面出现横向滑移时可能导致自松，因此先确定所需预紧力。
2. Grade and material. Select high-strength fasteners, including grade 12.9, to suit joint loads, mating materials and assembly conditions. A higher property class is not always the better choice.选强度等级与材质。结合关节载荷、被连接材料和装配工况选择高强度紧固件（含 12.9 级），等级越高不一定越合适。
3. Head and drive. Use low-head or countersunk heads where space is tight; prefer hexalobular drives for automated driving and small sizes.选头型与驱动。空间紧凑用低头或沉头；自动锁付和小规格优先梅花驱动。
4. Size and thread engagement. Into aluminium or magnesium housings the internal thread is often the weak point; add a wire thread insert where engagement is short. Calculate critical joints per VDI 2230.确定规格与旋合长度。铝、镁合金壳体的内螺纹往往是薄弱点，旋合长度不足时加钢丝螺套；关键连接按 VDI 2230 计算。
5. Locking and finish. Choose the locking method by vibration level and service needs, and avoid electroplating on grade 12.9 screws.选防松方式与表面处理。按振动程度和拆装需要选防松方式；12.9 级螺钉避免电镀。

Grades and materials强度等级与材质要点

• Grade 12.9 alloy steel suits highly loaded steel joints; re-evaluate the grade for aluminium or magnesium parts, fatigue, low-head designs and installation conditions.12.9 级合金钢适用于高载荷的钢制连接；连接铝、镁合金母材，或考虑疲劳、低头结构和安装条件时，应重新评估等级。
• Stainless steel (A2 / A4) is weaker than 12.9, so preload at the same size is lower; re-check before substituting.不锈钢（A2 / A4）强度低于 12.9 级，同规格下预紧力更小，替换前请重新校核。
• Titanium suits weight-sensitive positions; grade, strength, surface treatment and mating materials are confirmed to drawing.钛合金适合对重量敏感的部位；材质牌号、强度、表面处理及配合材料按图纸确认。
• Where low magnetism is required, accept against grade, processing condition and the specified magnetic properties.有低磁要求时，按牌号、加工状态和规定的磁性能指标验收。

Head types and drives头型与驱动

• Hexalobular socket head (ISO 14579 / GB/T 2671.2): high torque transfer and little cam-out, ideal for automated driving. ISO 14579 starts at M2; M1.6 hexalobular screws are custom parts defined by drawing.内六角梅花圆柱头（ISO 14579 / GB/T 2671.2）：传扭能力高、不易打滑，适合自动锁付。ISO 14579 从 M2 起，M1.6 梅花头为按图纸定义的定制件。
• Low-head socket (DIN 7984, DIN 6912): saves axial space, but head load capacity and drive depth are lower than a standard cap screw. The two standards differ and are not interchangeable.低头内六角（DIN 7984、DIN 6912）：节省轴向空间，但头部承载和驱动槽深度低于普通圆柱头；两个标准不同，不可直接互换。
• Flat head socket (ISO 10642): reduced loadability due to head design; do not design to the tensile load of a standard cap screw, and verify countersink alignment.内六角沉头（ISO 10642）：头部设计导致承载能力降低，不能按普通圆柱头螺钉的拉力设计，并需核查沉孔贴合。
• Precision screws M1.0 – M2.5: keep coatings thin, watch batch consistency of head height and drive depth, and validate for automated driving.精密螺钉 M1.0 – M2.5：表面处理选薄层，关注头高和驱动深度的批次一致性，并做自动锁付验证。

Anti-loosening防松方案

What to send with an RFQ询价时请提供

• Drawings or BOM, applicable standards, thread size and length图纸或 BOM、标准号、螺纹规格与长度
• Property class or material, finish and locking requirements强度等级或材料、表面处理、防松要求
• Mating materials, target preload or tightening conditions, working environment被连接件材料、目标预紧力或拧紧条件、工况环境
• Inspection criteria, sample quantity and annual demand检验要求、样品数量与年用量

See the full range by position on our Fasteners for Robotics page, or search by standard in Product Search.各部位常用紧固件详见 紧固件在机器人上的应用，也可在 产品查询 按标准号检索。