Split Spring Lock Washer ASME B18.21.1 Inch Series

Our Split Spring Lock Washer ASME B18.21.1 Inch Series is a helical split lock washer designed specially for inch-size fastener sets. With an open split structure, it creates spring tension after tightening to prevent loosening caused by vibration, impact and temperature change. We supply a full range of inch sizes, multiple material and surface treatment options to match different industrial working conditions. It is widely used together with UNC hex bolts, cap screws and heavy hex nuts for stable locking connection.

Raw Material Selection Standard

High-grade raw material is the foundation of stable locking performance. We carefully select spring steel and stainless steel raw materials sourced from certified and qualified steel mills with stable chemical composition. Every incoming batch will undergo strict laboratory tests covering hardness, tensile strength and elasticity before being released for production. Any raw material blanks that fail to meet our technical standards will be rejected and returned directly to suppliers, so we can effectively eliminate hidden risks such as elastic fatigue, permanent flattening and locking failure of finished washers under vibrating working conditions.

Basic Specification Table

Production & Quality Control

Every production step follows fixed process flow: blanking, forming, heat treatment, surface finishing and final sorting. Each workstation carries out self-inspection during processing to control product quality in real time and reduce manufacturing defects. Our professional QC team conducts spot checks on finished goods, focusing on dimension, opening gap and elasticity to ensure consistent locking performance. We adopt standard random sampling rules for every production batch, and any non-conforming washers will be segregated and handled properly. We keep complete inspection records for each lot to support full traceability for overseas buyers.

Surface Treatment Options Table

Key Features

- Built-in helical split structure, generates continuous spring pressure to resist loosening under vibration.

- Strictly produced following ASME B18.21.1 standard, dimension tolerance controlled for perfect fit with inch fasteners.

- Flexible material and finish selection to meet clients’ budget and environment demand.

- Available in mixed sizes or single-size bulk packing, supports custom labeling for wholesalers and distributors.

Installation Tips

Correct installation matters greatly for the final locking effect of the washer. The sharp edge of the split opening should face against the rotation direction of nut tightening, which helps the edge bite into the contact surface and deliver reliable anti-loosening friction. Do not apply excessive torque to over-compress the washer until it is completely flattened. Once the helical structure is fully pressed flat, it can no longer maintain spring tension and will permanently lose its anti-loosening spring force under vibration.

Application Scenarios

This Split Spring Lock Washer ASME B18.21.1 Inch Series is a common locking fastener across many North American projects. It fits machinery manufacturing, steel structure, fence, photovoltaic frame, pump and valve assembly, automotive auxiliary parts and general equipment maintenance. For dynamic load and vibration-heavy positions, it is highly recommended to use this lock washer together with matched high-strength inch bolts and nuts.

Matching Suggestion

This lock washer is normally assembled between the nut and the fastened contact surface. For carbon steel split spring lock washers, we suggest pairing them with matching carbon steel inch fasteners for balanced performance. If you select stainless steel split spring lock washers, please choose stainless steel bolts and nuts as supporting sets. This matching principle helps effectively avoid galvanic corrosion caused by contact between dissimilar metals under humid or corrosive environments.

Storage Guidance

Store the split spring lock washers in a dry, clean and well-ventilated warehouse to preserve their original performance. Keep them far away from humid surroundings, salty mist and corrosive gas that may trigger premature rust. Specially, galvanized carbon steel washers shall avoid prolonged exposure to open air, as such exposure will easily lead to the generation of white rust and damage the surface anti-corrosion layer.

FAQ

Q1: What is the difference between split spring lock washer and flat washer?

A: Flat washer mainly distributes pressure; the Split Spring Lock Washer ASME B18.21.1 Inch Series focuses on anti-loosening by spring tension. They are often used together.

Q2: Can you provide mixed size packs for resale?

A: Yes, we support mixed inch size packages, customized bag labels and export neutral packing for distributors.

Q3: What is your lead time for bulk order?

A: Standard sizes are kept in stock for fast delivery. For special surface treatment or large bulk orders, the lead time will be confirmed according to your quantity.

Q4: Is this washer compatible with metric bolts?

A: This series follows ASME inch standard, best matched with UNC/UNF inch fasteners. We do not recommend using it with metric bolts.