Mechanical Fasteners & Lifting Components

1

Monkey Board Pin

φ50×105

111.53.00.04

40Cr Alloy Steel (Quenched & Tempered)

1. High-frequency impact during drilling rig monkey board operation; 2. Stress corrosion caused by drilling fluid (containing sulfide and chloride); 3. Wear from relative friction with bushing under dynamic load.

1. Conduct magnetic particle inspection every 300 working hours to detect hidden cracks; 2. Apply anti-corrosion grease (compatible with drilling fluid) to the pin surface before installation; 3. Ensure the matching bushing is intact; replace the bushing simultaneously if excessive wear is found; 4. Avoid over-tightening during installation to prevent thread deformation.

2

Safety Pin

φ10×75

111.53.00.05

304 Stainless Steel

1. Fatigue failure due to repeated insertion and extraction during equipment maintenance; 2. Corrosion in humid and dusty construction environments; 3. Shear damage caused by exceeding the rated shear force due to improper matching.

1. Select pins that match the rated shear force of the connected components; do not replace them with pins of smaller diameters; 2. Clean the pin hole and pin surface before each use to remove debris and corrosion products; 3. Store unused pins in a dry and sealed container to avoid moisture; 4. Do not use pliers to knock the pin violently during installation to prevent bending.

3

Pin

φ30×80

111.53.250.01

45# Carbon Steel (Surface Phosphating Treatment)

1. Abrasive wear caused by sand and gravel in outdoor construction environments; 2. Hydrogen embrittlement due to improper electroplating process; 3. Bending deformation caused by lateral load exceeding the design limit.

1. Conduct regular wear measurement; replace the pin when the diameter wear exceeds 0.5mm; 2. Use phosphating treatment instead of electroplating in humid environments to avoid hydrogen embrittlement; 3. Install positioning sleeves to limit lateral displacement and prevent excessive lateral load; 4. Avoid using the pin in high-temperature environments (exceeding 200℃) to prevent material performance degradation.

4

Cotter Pin

3.2×30 (GB91-86)

3.2×30GB91-86

65Mn Spring Steel

1. Fatigue fracture due to repeated elastic deformation during equipment vibration; 2. Corrosion caused by long-term exposure to rainwater and chemicals; 3. Shear damage due to improper opening angle (too large or too small).

1. The opening angle after installation should be controlled at 60°-90° to ensure locking force without excessive stress; 2. Replace cotter pins immediately if there are signs of rust or elastic fatigue; 3. Use stainless steel cotter pins in chemical or marine environments; 4. Do not reuse cotter pins that have been bent and opened multiple times.

1

Bolt

M12×40 (GB31.1-88, 8.8 Grade)

M12×40GB31.1-88(M12×40-8.8)

40CrMo Alloy Steel (Heat Treated)

1. Thread wear caused by repeated assembly and disassembly; 2. Stress corrosion cracking in high-humidity and corrosive environments; 3. Torsional shear failure due to excessive tightening torque exceeding the material's yield strength.

1. Use a torque wrench to control the tightening torque according to the 8.8-grade bolt standard (recommended torque: 45-55 N·m); 2. Apply anti-seize agent to the thread surface in high-temperature environments to prevent thread jamming; 3. Conduct ultrasonic testing regularly to detect internal cracks; 4. Avoid using in environments with chloride ion concentration exceeding 50ppm to prevent stress corrosion.

2

Slotted Nut

M12 (GB6178-86, 8 Grade)

M12GB6178-86(M12-8)

35# Carbon Steel (Carburizing Quenching)

1. Slot deformation caused by improper use of tools during cotter pin installation; 2. Thread stripping due to uneven force during tightening; 3. Corrosion-induced locking of thread pairs.

1. Use a slotted screwdriver or special tool to install the cotter pin; do not knock the slot directly; 2. Ensure the nut is perpendicular to the bolt during tightening to avoid uneven force; 3. Clean the thread before installation and apply anti-corrosion oil; 4. Replace the nut if the slot width wear exceeds 0.3mm or the thread is damaged.

3

Washer

12 (GB97.1-85)

12GB97.1-85(12)

Q235 Carbon Steel (Zinc Plated)

1. Deformation caused by excessive clamping force; 2. Corrosion of the zinc plating layer in humid environments, leading to rust; 3. Abrasive wear between the washer and the connected component surface.

1. Do not stack multiple washers to increase the clamping thickness; use a single washer that matches the bolt specification; 2. Check the zinc plating layer for damage before installation; replace if there is obvious scratch or rust; 3. Ensure the connected component surface is flat and free of debris to avoid uneven stress on the washer; 4. In high-corrosion environments, use hot-dip galvanized washers instead of electro-galvanized ones.

1

Lifting Tackle

H1x1KBL

-

High-Strength Alloy Steel (Forged, Tempered)

1. Wear of pulley bearings due to lack of lubrication during high-frequency use; 2. Fatigue damage of the hook under repeated load; 3. Corrosion caused by exposure to rainwater and harsh weather in outdoor operations.

1. Lubricate the pulley bearings with lithium-based grease every 50 working hours; 2. Conduct non-destructive testing (NDT) on the hook every 6 months to detect fatigue cracks; 3. Do not exceed the rated load (1T for H1x1KBL); avoid overloading hoisting; 4. Store in a dry and covered area when not in use; cover with a protective cover to prevent dust and moisture.

2

Pulling Device

-

111.53.256.00

42CrMo Alloy Steel (Surface Nitriding Treatment)

1. Wear of the traction interface due to relative sliding with the pulled component; 2. Internal stress concentration caused by improper traction angle, leading to deformation; 3. Corrosion of the nitriding layer in acidic environments.

1. Ensure the traction angle is within ±5° of the horizontal to avoid lateral stress; 2. Install a wear-resistant pad between the traction interface and the pulled component to reduce direct friction; 3. Check the nitriding layer for peeling or damage regularly; re-nitriding if necessary; 4. Avoid using in environments with pH value less than 5 to prevent acid corrosion.

3

Chainlet

9 L=400 (GB5802-86, φ9-400)

9 L=400GB5802-86(φ9-400)

20Mn2 Alloy Steel (Heat Treated, Shot Blasted)

1. Wear of chain links due to mutual friction during load-bearing; 2. Fatigue failure caused by repeated bending and tension; 3. Corrosion and pitting caused by contact with water and chemicals.

1. Check the chain link wear regularly; replace the chainlet if the wear of the chain link diameter exceeds 10% of the original diameter; 2. Avoid sudden loading or unloading to reduce impact load on the chain; 3. Clean the chain with diesel oil after use in wet or chemical environments, then dry and apply anti-rust oil; 4. Do not use the chainlet in high-temperature environments exceeding 300℃ to prevent material softening.

1

Clip

60×φ30×φ3

111.53.00.03

Stainless Steel 316L

1. Elastic fatigue of the clip body due to repeated clamping and loosening; 2. Corrosion caused by long-term exposure to salt spray, humidity, or chemical media; 3. Wear of the inner clamping surface due to relative movement with the clamped component.

1. Do not exceed the maximum clamping range during installation; avoid over-clamping to prevent permanent deformation of the clip body; 2. In marine or salt spray environments, regularly check for corrosion spots and clean with a stainless steel cleaner; 3. Install a rubber gasket between the inner clamping surface and the clamped component to reduce friction and avoid scratching the clamped component; 4. Replace the clip immediately if there is obvious deformation or loss of elasticity.