Overview
Electrogalvanized bolts are standard fasteners coated with a thin layer of zinc through electrolytic deposition. This process ensures even coverage and moderate corrosion protection, making them suitable for indoor or mildly corrosive environments. Compared to hot-dip galvanizing, electrogalvanizing offers a smoother finish and tighter dimensional tolerances, which is critical for precision assemblies. These bolts are commonly graded as 4.8, 8.8, or 10.9, indicating their tensile strength.
Structure and Working Principle
The bolt consists of a threaded shaft and head (hex, flange, or other types), with a zinc layer typically 5-25µm thick. The electroplating process involves submerging the cleaned bolt in a zinc electrolyte solution and applying direct current to deposit zinc ions onto its surface. This coating acts as a sacrificial layer, corroding before the underlying steel. The zinc also forms a passive layer (zinc oxide/carbonate) upon air exposure, further slowing corrosion. Thread tolerances adhere to ISO 965 standards for compatibility with nuts.
Key Features
Electrogalvanized bolts provide balanced cost and performance. Their smooth coating minimizes friction during installation, unlike rough hot-dip coatings. The plating thickness is controllable, usually ranging from 5µm for light duty to 25µm for harsh conditions. These bolts withstand salt spray tests for 72-200 hours (per ASTM B117), depending on thickness. They maintain thread precision better than hot-dipped alternatives, making them preferable for machinery where vibration resistance matters.
Application Areas
Common applications include electrical enclosures, HVAC systems, and furniture assembly where moderate moisture resistance suffices. Automotive manufacturers use them for non-critical underbody components. In construction, they fasten steel framing and roofing sheets. Their affordability makes them popular in bulk fastening projects, though they’re less suitable for marine or chemical plant use compared to stainless steel or hot-dip galvanized alternatives.
Maintenance and Precautions
Inspect bolts annually for white rust (zinc oxide) or coating wear, especially in humid areas. Avoid using with dissimilar metals (e.g., copper) to prevent galvanic corrosion. Clean with mild soap and water—never acid-based solutions. For high-stress applications, retorque after 6-12 months as the zinc coating may compress slightly. Store in dry conditions; oxidized bolts lose up to 30% of their anti-corrosion effectiveness. Never weld electrogalvanized bolts—zinc fumes are toxic.
B2B Procurement Guide
Specify coating thickness (e.g., 8µm for indoor use, 15µm for outdoor), thread standards (metric/imperial), and strength grade. Bulk orders (10,000+ units) often reduce costs by 15-20%. Leading manufacturers include ITW, Bossard, and Fastenal. Request salt spray test reports and RoHS compliance certificates. For export, ensure packaging meets ISPM 15 for wooden crates. MOQs typically start at 1,000 pieces; lead times range from 2-6 weeks for custom sizes. Sample testing is recommended to verify coating adhesion (per ISO 4520).
Related Manufacturers
- 主营：自攻螺丝、燕尾螺钉、圆形弹垫、螺栓螺丝、六角螺栓、焊接螺栓、螺栓垫片、双头螺栓、注塑螺栓、自钻螺钉、螺母垫片、活节螺丝、六角螺母、法兰螺母、加大平垫、六角螺丝、法兰螺帽、化学锚栓、压板螺母、自钻螺丝、钻尾螺钉、拉铆螺母、导向螺钉、钻尾螺丝、螺丝螺母
- 主营：轨道压板、轨道固定件、锻造压板、鱼尾螺栓、地脚螺栓、轨道垫板、压板总成、焊接压轨器、焊接轨道压板、锻造压板总成、9120压板总成、9220压板总成、柔性轨道压板、伸缩缝夹板、钢轨销售、加工钢轨、矿山轨、连接夹板、鱼尾板、道夹板
- 主营：避雷塔、烟囱塔、监控塔、电力架构、电力构架、电力角钢塔、气象塔、路灯杆、烟囱护架、防火监控、仿生树塔、监控铁塔、钢结构支架、仿生通讯塔、消防训练塔、单管景观塔、三角避雷塔、办公楼景观塔、高压拉线避雷塔、移动通讯信号塔、防爆消防攀爬塔、基站一体化机房
- 主营：转角塔、直线塔、耐张线夹、镀锌锤头、备份线夹、光缆防晕、悬垂线夹、光缆防振锤、塑料接头盒、光缆接头盒、单长尾抱箍、光缆防护金具、光缆耐张金具串、安全备份线夹、全张力接续条
- 主营：不锈钢螺丝、304不锈钢螺丝、地脚螺丝、不锈钢螺栓、304不锈钢螺栓、不锈钢内六角螺栓、不锈钢外六角螺栓、不锈钢膨胀螺栓、地脚螺栓、预埋螺栓、热镀锌预埋螺栓、预埋地脚螺栓、热镀锌地脚螺栓、镀锌牙条、高强度牙条、高强度丝杆、高强度丝杠、皮带轮
- 主营：圆柱销、圆锥销、斜垫片、开口销、斜垫圈、铆螺母、弹簧垫圈、压铆螺柱、凹凸垫圈、开口挡圈、带孔销轴、凹凸垫片、波形垫圈、子母铆钉、自锁垫圈、黑色铝拉钉、双面齿垫圈、半空心铆钉、五金紧固件、蝶形压花垫圈、双耳止动垫圈、沉头实心铆钉、平头实心铆钉、沉头抽芯铆钉、单耳止动垫圈
- 主营：楼梯护角、钢筋马镫、止水钢板、止水螺栓、穿墙螺栓定制、钢筋套筒定制
- 主营：螺母、光伏、高强度、螺栓、热镀锌、光伏配件
- 主营：圆柱销、止退垫、防松螺母、镀锌丝杠、膨胀螺栓、吊环螺栓、花篮螺栓、热镀锌垫片、销轴卡簧、膨胀螺丝、轴承卡簧、螺纹丝棒、薄头螺钉、开口挡圈、尼龙螺母、弹性挡圈、工业齿条、法兰螺母、轴用卡簧、五金垫片、碳钢螺丝、六角铜螺母、不锈钢平键、不锈钢牙条、钢丝绳卡头
- 主营：铁附件、横担、耐张线夹、电力金具、抱箍、重锤片、绝缘子、调整板、连接金具、拉线抱箍、碗头挂板、二线墙担、角铁横担、直角挂板、球头挂环、拉线棒、悬垂线夹、光缆金具、导线金具、防震锤、楔形线夹、UT 线夹、联板、U型挂环
- 主营：全螺纹螺柱、预埋钢板、预埋件、高强度螺栓、地脚螺栓、热镀锌拉条、镀锌拉条、双头螺栓、螺栓、焊板地脚螺栓、栓钉、剪力钉、螺母、高强度螺母
- 主营：法兰螺栓、标准件、桥架螺丝、不锈钢螺丝
- 主营：热浸锌丝杆、钢结构螺丝、钢结构大六角、管片螺栓、钢结构大六角螺栓、高强度螺栓、双头弧形螺栓、热镀锌丝杠、地脚螺栓、热镀锌丝杆、达克罗盾构管片螺栓、地脚螺栓预埋件、9字螺栓、热镀锌通丝吊杆m10、钢结构螺栓、m20高强度螺栓、10.9级摩擦型螺栓、螺栓扭剪型、热镀锌m8牙条、镀锌通丝吊杆、大六角钢结构、8厘吊杆、盾构隧道的管片、丝杆螺杆
- 主营：地铁管片、热浸锌牙条、折叠地脚笼紧固件、钢结构大六角螺栓、钢结构扭剪型螺栓、热镀锌螺栓、管片螺栓、热镀锌丝杠、弧形双头螺栓、热渗锌螺栓、镀锌螺丝27、热镀锌螺栓M30、高强度风电螺栓、地脚螺栓、M24地脚螺栓、焊板地脚螺栓预埋件、10.9级扭剪螺栓、大六角螺栓、钢结构螺栓、国标螺栓10.9级、10.9S螺栓、高强螺栓10.9s、地脚螺丝、20*70扭剪高强螺、gb1228
- 主营：盆式橡胶支座、板式橡胶支座、桥梁伸缩缝、电力高铁抱箍、梳齿板伸缩缝、桥梁卸落块、声测管
- 主营：化学螺栓、预埋螺栓、钢结构螺栓