Extension Spring (Reverse Round Hook)

Specifications

How to choose Springs

Points to check when selecting, with the values for this product (Extension Spring (Reverse Round Hook)).

1. 1. Select the Spring Rate from the Required Force

   The spring rate k is the load required to deflect the spring by 1 mm. Multiply it by the deflection at installation and at operation to confirm that the required force can be obtained. Listed products range widely from 0.007 to 9.91 N/mm, and a margin should be allowed for variation, including the spring rate tolerance (for example, ±10%).

2. 2. Keep Within the Maximum Load and Deflection Limits

   This product: Maximum load 45〜120 N

   Using the spring beyond its maximum load or maximum deflection causes set (permanent deformation) or breakage. Confirm that the load at the maximum point of the operating stroke is within the maximum load, and for compression springs, that the solid height is not reached.

3. 3. Installation Space, Outside Diameter, and Free Length

   This product: Outer diameter D 12〜20 mm

   Check that the outside diameter fits the hole or housing, and that the inside diameter does not interfere with the shaft it passes over (applicable shaft diameter). The free length is the length under no load; the difference from the installed length is the initial deflection. Because the coil diameter changes under load, allow sufficient clearance.

4. 4. Select a Material Suited to the Operating Environment

   Piano wire SWP-A has high strength but is prone to rust, and many versions are supplied with rust-preventive oil treatment. For humid environments or environments subject to washing, stainless steel such as SUS304-WPB is a candidate. For strongly corrosive environments such as seawater, titanium is a candidate.

5. 5. Extension Springs: Initial Tension and Hook Shape

   Close-wound extension springs have initial tension, the load required before the spring begins to extend. For applications requiring movement with a small force, check the initial tension value. Also check that the hook shape, such as reverse loop, 90-degree, or 180-degree, matches how the mating part is engaged.

6. 6. Torsion Springs: Angle and Arm Direction

   For torsion springs, check the torque at the operating angle (torsion spring rate × angle) and the arm length. The winding direction should match the direction of twist, and it is common to use the spring in the direction that winds it up. For free-size products, also specify the bending direction.

This guide was written by AI based on the listed products' documents and specification items.

About Springs and all products

Description

Extension coil spring with reverse round hooks on both ends. Spring constant, maximum load, and maximum extension are listed.

FAQ

Q. What are the ranges of outer diameter, wire diameter, and free length for the 43-T2xx Extension Spring (Reverse Round Hook)?

A. Outer diameter D is 12 to 20 mm, wire diameter d is 1.6 to 2.5 mm, and free length L is 25 to 60 mm.

Q. What is the maximum load of the 43-T2xx Extension Spring (Reverse Round Hook)?

A. The maximum load is 45 to 120 N.

Q. What shape is the 43-T2xx Extension Spring (Reverse Round Hook)?

A. It is an extension coil spring with reverse round hooks on both ends. Spring constant, maximum load, and maximum extension are listed.

Written by AI based on the content of the source documents.

Source documents

• Catalog スプリングネット 製品カタログ（ばね類） 178 pages Open page 70
  Found on: https://www.samini.co.jp/catalog_list/