Double End Threaded Rod Safety Operation Manual

What precautions should be taken when using double end threaded rod?

double threaded rod (double-ended threaded rods) are core components for mechanical connections and building supports. Improper handling can easily lead to loosening, breakage, and even accidents. The following summarizes precautions during use.

Inspect the double end threaded bar regularly (once a month) and replace immediately if rust or deformation is detected. Following these four tips can triple the life of the screw and ensure zero accidents!

1. Selecting the Right Double-Ended Screw Specifications

Application	Recommended Material	Diameter Selection	Safe Load Capacity Reference
Furniture/Light-Load Equipment	Galvanized Steel	M6-M8	≤200kg
Mechanical Equipment/Scaffolding	Quenched 45# Steel	M10-M16	1-5 tons
Chemical/Food Industry/Humid Environments	304 Stainless Steel	≥M12	Corrosion Resistance >3 times that of Ordinary Steel

2. Preventing Loosening

Problem: Equipment vibration and load impact can cause ordinary nuts to gradually rotate and fall off. Solution:
Required anti-loosening accessories:
Spring washers (lowest cost): Use spring force to offset vibration.
Double-nut locking (most reliable): Two nuts tightened together create a mechanical self-locking mechanism.

Nylon lock nuts (maintenance-free): Embedded plastic rings increase frictional resistance.

Painful lesson: A construction site scaffolding, lacking anti-loosening nuts, experienced nighttime vibrations that caused a stud screw to fall off and collapse!

Tearful case: A factory used an M8 standard stud screw to support 800kg of equipment. Three days later, the threads tore, destroying the equipment!

III. Lubrication
Problems: Rust, seizure, thread wear, and increased adjustment resistance.

Correct operation:

Initial lubrication: Apply butter or molybdenum disulfide lithium grease to the double threaded bar.

Regular maintenance:

Indoor equipment: Regrease every six months.

Outdoor/humid environments: Spray with a rust-inhibiting lubricant (such as WD-40) every three months.

Contraindications:

Regular grease is prohibited for food machinery! Switch to food-grade white oil.

Chemical plants prohibit the use of corrosive greases; opt for fluorinated grease.

4. Tightening Force: You can’t afford the cost of thread stripping.

Fatal Practice: Using an extension wrench to tighten violently! This can deform and fail the threads of a double end threaded rods and studs.

Scientific Method:

Manual Pre-Tightening: First, hand-tighten the nut until it’s snug.

Tool Reinforcement:

Lead screws under M12: Use a wrench for ≤ half a turn.

Emergency Measures: If thread stripping occurs, replace it immediately! Never force it into place by welding or injecting glue.