Product Specifications
| Model / Specification | M2 – M20 |
| Material | Stainless Steel |
| Size | 2 | 2.5 | 3 | 4 | 5 | 6 | 8 | 10 | 12 | (14) | 16 | (18) | 20 | |
| d | Min. | 2.2 | 2.7 | 3.2 | 4.3 | 5.3 | 6.4 | 8.4 | 10.5 | 12.5 | 14.5 | 16.5 | 19 | 21 |
| Max. | 2.45 | 2.95 | 3.5 | 4.6 | 5.6 | 6.76 | 8.76 | 10.93 | 12.93 | 14.93 | 16.93 | 19.52 | 21.52 | |
| dc | Min. | 4.2 | 5.2 | 5.7 | 7.64 | 9.64 | 10.57 | 14.57 | 17.57 | 19.98 | 23.48 | 25.48 | 29.48 | 32.38 |
| Max. | 4.5 | 5.5 | 6 | 8 | 10 | 11 | 15 | 18 | 20.5 | 24 | 26 | 30 | 33 | |
| t | 0.3 | 0.3 | 0.4 | 0.5 | 0.6 | 0.6 | 0.8 | 1 | 1 | 1.2 | 1.2 | 1.5 | 1.5 | |
| Number | Min. | 6 | 6 | 6 | 8 | 8 | 8 | 8 | 9 | 10 | 10 | 12 | 12 | 12 |
| Weight per 1000 Pcs (Steel) ≈ kg | 0.02 | 0.02 | 0.04 | 0.09 | 0.18 | 0.19 | 0.54 | 0.92 | 1.08 | 1.94 | 2.07 | 3.66 | 4.34 | |
INTERNAL TOOTH LOCK WASHER — PRODUCT INTRODUCTION
The Internal Tooth Lock Washer is a spring washer that utilizes the principle of mechanical bite to achieve anti-loosening performance. It is installed under the bolt head or nut, with several sharp locking teeth along the inner circumference, angled toward the screw shank direction. When the nut is tightened, these teeth elastically deform and firmly bite into the screw shank or mating support surface, generating extremely high friction to effectively prevent the nut from rotating loose due to impact or vibration. The commonly used material is 65Mn spring steel (quenched and tempered), with finishes commonly in black oxide or zinc plating.
I. PRODUCT FEATURES
Multi-Tooth Internal Bite Design: The inner circumferential teeth are sharp and continuously twisted, capable of providing persistent spring-like elasticity — automatically biting into the fastened surface upon installation.
Excellent Elasticity: High-manganese (Mn) quality spring steel, strictly heat-treated to maintain hardness stable in the HRC 40–50 range, resistant to permanent compressive deformation.
Compact and Lightweight: Outer diameter small, mainly within wrenching flats of bolt head or nut — suitable for countersunk holes or cylindrical surface mounting.
Uniform Surface Coating: Coatings (such as zinc) or oxide films uniformly cover tooth surfaces, primarily serving rust-prevention — locking achieved through metal friction after tooth tips bite in.
II. PRODUCT ADVANTAGES
Reliable Anti-Loosening Effect: Multi-point circumferential bite with more uniform force distribution — will not fully open and fail the way split lock washers can.
Easy Installation: Simply slide onto the screw — no precise positioning or bending required, significantly improving production line assembly efficiency.
Protects Small-Dimension Screws: Well concealed beneath the head — aesthetically pleasing and prevents snagging on clothing or cables.
Anti-Loosening Combined with Electrical Contact: Sharp tooth tips can pierce paint layers or oxide films, providing auxiliary grounding effect on certain equipment.
III. APPLICATIONS
Precision Electronics: Household appliances, communication equipment, computer chassis.
Automotive: Instrument panels, headlamp assemblies, sensor brackets, electric seats.
General Machinery: Small motor end covers, instrument housings, pneumatic components, pump bodies.
Hardware & Furniture: Desk chairs, drawer slides, lock hardware.
