Excavator Tooth Adapter 208-939-3120 208-934-7120 Earth Moving Machinery Spare Parts

Pin precision and service life requirements

The precision, service life and technical requirements of pins in the field of construction machinery are as follows (key indicators are based on international/national standards and industry practices) :

I. Core Requirements for Precision

Dimensional tolerance ‌

The diameter tolerance of the cylindrical pin should be controlled within ‌±0.02mm‌, and the length tolerance is ‌≤0.02mm‌, which should be achieved through coreless grinding process.

The conical pin adopts the standard taper of ‌1:50 ‌ (GB/T 117-2000) to ensure the accuracy of the self-locking position.

The servo press-fitting system can ensure the press-fitting position accuracy ‌±0.01mm‌ (full closed-loop control), and the pressure accuracy ‌±0.5%FS‌.

Process assurance ‌

High-precision pins need to be ground, with a surface roughness of ≤Ra0.4μm, to reduce assembly friction loss.

Ii. Factors Affecting Lifespan

Materials and processing techniques ‌

Material type ‌ ‌ processing technology ‌ ‌ applicable scenarios ‌ ‌ lifespan advantage ‌

The surface hardness of 45 steel after carburizing and quenching for ordinary heavy-duty use is ≥58HRC, and its wear resistance is enhanced

304 stainless steel can withstand salt spray corrosion for more than 500 hours in corrosive environments such as agricultural machinery and mining after solution treatment

The fatigue strength of the high-precision transmission position of bearing steel (such as GCr15) after overall quenching is increased by 30%

Fail-proof design ‌

The safety pin needs to be heat-treated to ‌30-36HRC‌ and will break preferentially as an overload protection element.

The cotter pin adopts an elastic structure to absorb vibration energy and reduce the risk of loosening and breaking.

Iii. Key Technical Specifications

Strength verification ‌

The heavy-duty pin shaft needs to undergo a ‌ radial shear force test ‌ (≥800MPa), and the transmission pin needs to conduct a torque load simulation test.

In the high-frequency vibration scenario, the displacement of the conical pin needs to be verified to be less than 0.05mm after ‌10 cycles ‌.

Environmental adaptability ‌

For hot and humid working conditions, ‌304 stainless steel pin ‌ (GB/T119.2) is preferred. The salt spray test shows no rust for no less than 96 hours.

In a low-temperature environment (-40℃), the toughness of the material needs to be tested to prevent brittle fracture.

Selection suggestion ‌ :

Precision positioning scenario: Select grinding grade cylindrical pins (GB/T119.1) in conjunction with servo press-fitting;

Corrosive environment: 304 stainless steel pin + anti-loosening split pin combination;

Overload: Dual protection with 45 steel quenched pin and safety pin.