Spring for sectional industrial door

Introduction to Torsion Springs

• Sizes: 1-3/4", 2", 2-5/8", 3-3/4", 5-1/4", 6"

• Materials: 72B, 82B, 60Si2Mn, 55SiCr, supplied by well-known domestic brands

• Process: Cold rolling - Medium temperature tempering - Surface treatment - Installation of end caps - Labeling - Packaging

Standards:

• Inner diameter tolerance of torsion springs: +/-1%

• Clearance between coils: <0.2mm

• Tolerance of number of coils: +/-1%

• Life cycle test: >20000 cycles without fracture, load loss <15%

• Neutral salt spray test: >72 hours, no rust spots on surface (equivalent to 3 years)

Cold Rolling:

• Cold rolling process is a test for torsion springs to withstand extreme conditions without breaking

• Normal use requires about 65% of the force used in cold rolling, which has low efficiency and high cost.

• Automatic spring coiling machines produce springs that are unstable in their free state

Surface treatment methods:

Oil immersion, electroplating, electrophoresis, powder coating, etc.

End Caps:

•Made of high-strength alloy aluminum ADC12

•Different torsion spring models require different types of end caps

•End caps are divided into fixed end and adjustable end

•The adjusting end has a black mark on the left and a red mark on the right to help distinguish between left and right springs during installation

Tension Rods:

• Made of cold-drawn steel in two sizes: ∅25.4 and 31.75

• Surface treatment: natural or galvanized

Inner Lining:

• Three sizes available: ∅75, ∅95, ∅115

• Made of PVC using extrusion process

• Inner lining length is 10cm shorter than torsion spring length to effectively support the spring body and prevent deformation during normal operation