Overview
Lock bolts and nuts are engineered fasteners that maintain clamping force in dynamic applications. Unlike standard fasteners, they incorporate features like nylon inserts, deformed threads, or metal locking elements to resist vibrational loosening. These components are critical in industries where joint failure could lead to equipment damage or safety hazards. First developed during World War II for military vehicles, modern variants include prevailing torque nuts, flange serrations, and two-piece bolt systems. Their reliability makes them indispensable in automotive assembly lines, wind turbine construction, and railway infrastructure.
Structure and Working Principle
A typical locking nut uses one of three mechanisms: elastic deformation (e.g., nylon insert that creates friction), all-metal tooth designs that bite into mating threads, or chemical adhesives like threadlockers. Lock bolts may feature double nuts, castellated designs with cotter pins, or integrated washers with serrations. The working principle relies on overcoming the forces that cause standard fasteners to unwind. For example, a nylon-insert nut maintains constant radial pressure on the bolt threads, while wedge-lock washers create directional resistance against rotation. Torque values for installation are typically 20-30% higher than conventional fasteners to account for locking features.
Key Features
Vibration resistance is the primary characteristic, with some designs enduring over 5,000+ cycles in Junker vibration tests. Reusability varies by type—nylon inserts degrade after 5-10 uses, while all-metal designs often last indefinitely. Corrosion-resistant variants use 316 stainless steel or A4-grade materials for marine applications. Temperature tolerance ranges from -50°C to +150°C for polymer-enhanced types, with metal-only versions surviving up to +300°C. Many comply with industry standards like DIN 985 (nylon lock nuts) or NASM 25027 (aerospace lock bolts). Modern designs incorporate RFID tags for torque monitoring in Industry 4.0 systems.
Application Areas
Transportation sectors account for 60% of usage, including engine mounts, wheel assemblies, and aircraft control surfaces. In energy infrastructure, they secure wind turbine blades and solar tracking systems exposed to constant movement. Heavy equipment manufacturers use them in excavator booms and crusher machinery. Electronics applications include server racks and robotics joints where micro-vibrations could loosen connections. The construction industry employs them for seismic-resistant building frameworks and bridge expansion joints. Medical device manufacturers prefer stainless steel locking fasteners for MRI machines and surgical robots.
Maintenance and Precautions
Inspect locking elements before reuse—discard nylon insert nuts if the collar shows cracks or flattening. For metal lock nuts, check thread deformation using a go/no-go gauge. Always clean threads with a wire brush when reinstalling to maintain friction properties. Avoid mixing lubricants unless specified; some threadlockers require oil-free surfaces. Use calibrated torque wrenches to prevent galling in stainless steel variants. In corrosive environments, apply zinc-nickel plating or Dacromet coatings. Store chemical-adhesive types in sealed containers to prevent premature curing.
B2B Procurement Guide
Bulk purchases (1,000+ units) typically offer 15-40% cost savings. For OEM contracts, consider customized markings or packaging. Leading manufacturers include Nord-Lock (wedge systems), Schnorr (safety washers), and Hard Lock Industries (eccentric collar design). Technical specifications should include: thread size/grade (e.g., M12-8.8), locking method (mechanical/chemical), and certifications like ISO 16047 for torque testing. Just-in-time delivery options are available from distributors like Fastenal and Bossard. For critical applications, request vibration test reports and material certificates.
Related Manufacturers
- 主营：镍基合金、哈氏合金、膨胀合金、禁锢件、高温合金、英科洛伊、软磁合金、精密合金、马氏体时效钢、纯镍合金、不锈钢材料
- 主营：镍基合金、铜镍合金、蒙乃尔合金、N06600螺栓、因科耐尔合金、英科洛伊合金、高温合金、圆钢
- 主营：化学螺栓、预埋螺栓、钢结构螺栓
- 主营：A286、GH2132、SUH660、A490螺栓、GH4169、718、UNS N07718、INCONEL 718
- 主营：液压万能试验机、拉力试验机、电子万能试验机、高强螺栓检测仪、金属摆锤冲击试验机、冲击试验机、电子拉力试验机、疲劳试验机、微机液压万能试验机
- 主营：塔吊黑匣子、塔机模型、升降机模型、智能预警螺母、施工升降机AI数人数、升降机黑匣子监测、爬架监测、外墙脚手架监测、吊篮监测、楼层呼叫器、高支模监控、吊钩可视化、车辆未冲洗抓怕、深基坑监测、安全教育箱、大体积混凝土监测、实测实量监测、卸料平台模型、wifi智能答题、塔吊喷淋、高边坡监测、智能烟感、塔吊声光警示
- 主营：304不锈钢螺丝、2205不锈钢螺丝、310S不锈钢螺丝、304不锈钢螺栓、2205不锈钢螺栓、310S不锈钢螺栓、316不锈钢螺栓、304不锈钢螺母、热镀锌螺栓、316不锈钢螺丝、热镀锌螺丝、达克罗螺丝
- 主营：不锈钢索具、不锈钢钻尾钉、平键销、不锈钢螺栓、不锈钢螺母、不锈钢膨胀螺栓、圆螺母、扁螺母、轴销钉、收紧器、骑马卡、合螺丝、接地线、避雷针、支撑架、固定销、螺丝帽、护栏母、斜拉杆、套筒母、预埋件、靠背销、山形卡、定位销、球面垫
- 主营：建筑螺栓、地脚螺栓、不锈钢螺栓、建筑配件
- 主营：矿用挖掘机、矿用清仓机、矿用扒渣机、螺母、给煤机、无压风门、防水密闭门、气动隔膜泵、滚轮罐耳、皮带综保、矿用锂离子蓄电池电源、矿用翻车机、小型挖掘机、洒水降尘装置、司控道岔装置、空气炮、气动阻车器、气动卧闸、断带抓捕器、矿用防爆摄像仪、跑车防护装置、压风供水自救装置、防水剂、履带运输车、巷道修复机、矿用挖掘式装载机
- 主营：10.9S钢结构螺栓、Q235B地脚螺栓、8.8级高强度外六角、Q355B预埋锚栓、3米镀锌丝杆
- 主营：六角螺栓、螺母、紧固件
- 主营：不锈钢螺栓、热镀锌螺栓、高强度螺栓、光伏配件
- 主营：高强度螺栓、地脚螺栓、预埋件、异形件
- 主营：预埋件、焊接螺丝、厂房电力铁塔、地脚螺栓、不锈钢薄螺母、镀铜焊接螺母、防松螺母、高强度螺母、家具锥形螺母、卡式螺母、盲孔压铆螺母螺柱、内外牙螺母、热镀锌螺母、台阶螺母、四爪螺母、羊眼螺栓、T型螺母、法兰带垫螺母、外六角钻尾螺丝、304不锈钢喉箍、T型螺丝、不锈钢方形卡箍、马车螺丝、外六角内膨胀螺丝、不锈钢弹垫垫圈
- 主营：热镀锌丝杠、热浸锌牙条、热镀锌丝杆、钢结构大六角螺栓、钢结构扭剪型螺栓、钢结构螺栓、管片螺栓、高强度螺栓、弧形双头螺栓、地脚螺栓、地脚螺栓预埋件、m24地脚螺栓预埋件、地铁管片螺栓、达克罗盾构管片螺栓、10.9S高强度螺栓、大六角螺栓、国标螺栓10.9级、10.9S螺栓、预埋件、钢结构预埋件、M16地脚螺丝、m8吊顶丝杆、钢结构大六角、热镀锌m8牙条、热镀锌通丝吊杆m10
- 主营：全螺纹螺柱、预埋钢板、预埋件、高强度螺栓、地脚螺栓、双头螺栓、螺栓、螺母、高强度螺母、焊板地脚螺栓、热镀锌拉条、镀锌拉条、栓钉、剪力钉