M4 Adjustable Thread Locking Bolt

Qimao Metal Manufacturer is a professional M4 Adjustable Thread Locking Bolt supplier.

Adjustment Mechanism: The thread locking bolt threaded collar design providing continuous height adjustment from the retracted position to full extension. The collar features a knurled grip surface for manual adjustment or can be engaged with standard tools for precise positioning.

Locking System: Integrated friction lock that engages automatically when the adjustment collar is tightened against the mating surface. The locking torque is factory-preset within a specified range to ensure reliable hold without requiring specialized tooling for installation.

Material & Finish: Manufactured from medium-carbon steel with tensile strength rating suitable for M4 class 8.8 applications. Standard finish is clear zinc plating with trivalent passivation, offering corrosion resistance under normal indoor conditions.

Dimensional Data: Overall shank length measures 45.5mm in the fully closed position. The adjustment collar diameter is optimized to fit within standard clearance envelopes while providing adequate engagement surface for tightening.

Testing Compliance: Each batch undergoes functional testing including thread gauge inspection, adjustment cycle testing, and locking torque verification to maintain consistent quality.

Product Parameter (Specification)

Product Feature

• M4 Adjustable Thread Locking Bolt Integrated adjustment collar enables continuous height positioning without the need for additional spacer components or shims. This single-piece design simplifies inventory management and eliminates loose parts that could be misplaced during assembly or maintenance.

• Friction-based locking mechanism actively resists loosening under typical industrial vibration conditions. The locking force remains consistent across the full adjustment range, providing reliable hold even when the bolt is not torqued to its maximum clamping capacity.

• Zinc plating with trivalent passivation offers corrosion resistance suitable for indoor and protected outdoor applications. This finish also provides a consistent lubricity that prevents galling during repeated adjustment cycles.

• Single-piece construction eliminates separate locking nuts or washers that add complexity to assembly procedures. The unified design reduces the total number of components required per connection point.

Application

The M4 Adjustable Thread Locking Bolt for electronic enclosure assembly where internal component clearances vary due to PCB stack-up tolerances. The adjustable height feature allows assemblers to compensate for these variations without redesigning the enclosure.

• Small machinery guards and covers requiring secure attachment with occasional height re-leveling during maintenance. The locking mechanism holds the set position firmly while still allowing adjustments when equipment is serviced.

• Automotive interior trim panels where substrate surfaces are not perfectly flat across the part. This bolt provides consistent clamping force regardless of localized surface irregularities.

• Medical equipment chassis assembly where secure connections are mandatory and loose parts cannot be tolerated. The single-piece design satisfies both cleanliness requirements and safety standards for medical devices.

• Prototype and development builds where design changes frequently require different standoff heights. This bolt accommodates those changes without the need to source new fixed-length fasteners for each iteration.

Installation and Use guide

1. Start by verifying that the M4 Adjustable Thread Locking Bolt receiving threaded hole or nut meets class 6H internal tolerance. Hand-start the bolt for at least three full turns to confirm proper thread alignment before applying any torque.

2. Rotate the adjustment collar to your desired height position relative to the bolt shank, but keep it loose until the components being fastened are properly positioned against each other.

3. Once the panels or parts are brought into contact, advance the bolt into the mating thread until the adjustment collar touches the surface.

4. Final locking is achieved by torquing the bolt head while holding the adjustment collar stationary.

A torque wrench set to 2.8 to 3.2 N·m ensures consistent clamp force for M4 steel applications. After initial installation, inspect that the adjustment collar remains firmly seated against the workpiece. For disassembly, loosen the bolt head first to relieve clamp force, then rotate the collar if a different height is needed for future installations. The locking feature requires no maintenance and remains effective across the full adjustment range. For severe vibration environments, applying medium-strength threadlocker to the threads before final assembly provides additional security.