Extension Spring Hooks
Height of an extension spring hook
where:
L 0 | length of free spring [mm] |
L Z | length of spring coiled part [mm] |
Most frequently used hooks of extension springs
Hook type and dimension instructions | Image |
Half hook, o = 0.55 to 0.8 D 2 | 
|
Usually: d ≤ 6.3 mm, D >= 3.15 mm, i >= 9 |
Full loop, o = 0.8 to 1.1 D 2 | 
|
Used generally |
Full loop on side, o ≈ D 2 | 
|
When moving the force out of spring axis does not matter |
Full loop inside, o = 1.05 to 1.2 D 2 | 
|
Usually: d ≤= 10 mm, i >= 7 |
Raised hook, o = 1.2 D 2 to 30 d | 
|
Usually for: d = 0.5mm to 4 mm, o ≤ 100 mm |
Double twisted full loop, o ≈ D | 
|
Used generally |
Double twisted full loop on side, o ≈ D 2 | 
|
When moving the force out of spring axis does not matter |