Telescopic Spring Guards

Telescopic springs – also known as spiral springs or spring guards – have been developed to protect against accidents and mechanical damage wherever there are rotating parts, such as spindles or shafts. They are designed to follow the motion of the machine by spring force. Some of these springs can also be retrofitted.

  • Sizes: Presently, more than 1000 different standard sizes are available. See literature for sizes.
  • Material: High-quality blue spring steel strip (55-58 Rockwell) with rounded edges. Strength up to 1800 N/m². Thickness of 0.6 mm
  • Speed: Standard telescopic springs are designed for speeds up to 40 m/min.
  • Mounting/Orientation: Centering Flanges/ Collars which should be provided at the ends of the springs. They may be used for vertical, horizontal or diagonal motion. See tab below for more info.

Application Notes:

  • Intended to cover a spindle or ball screw on a machine tool. Compatible with oil.
  • Abrasive particles tend to find their way between the coils. Therefore, for grinding dust, we recommend a fabric bellows cover as an alternative method of protection.
  • Where coolants with a high water content are regularly used, we recommend telescopic springs made of stainless steel. These, however, have less spring force and can therefore not be made in all sizes.


Telescopic springs are wound differently for different mounting positions (horizontal or vertical), their extension (Lmax horizontal or Lmax vertical) depending on size. Please select the desired spring from our catalog and be sure to specify in your order whether you want H or V, so that we will make the right type of spring.

  • Horizontal mounting position: telescopic springs designed for horizontal use have greater overlap of coils than springs for vertical use to avoid “sagging”. The larger diameter should be where most chips occur.
  • Vertical and diagonal mounting position: due to the high extension forces involved, these springs (which act against the force of gravity) require greater extended length than horizontal telescopic springs. The larger diameter should be at the top. This avoids dirt from falling into the coils and has a self-cleaning effect.

Centering Flange
Centering should be provided at the ends of the springs to allow these to turn. The springs must be able to move freely and must not be fixed. The mounting sleeve and centering flange are not normally supplied with the springs. These flanges can be supplied as optional accessories.

Spring guards are easy to mount. A collar on one side and a pilot on the other are entirely sufficient. The springs must be able to move freely in them. They must not be fixed. If you wish to use a pilot and a collar, you should make allowance for the space needed. In other words, the inside diameter of the spring (D1) should in this case be chosen slightly larger, to make sure that the spring will fit over the pilot.

Telescopic springs are supplied tied down with wire. Caution: Springs are highly tensioned! Risk of injury! Be sure to follow the instructions, which are also supplied with the springs.

Dimensional Check: The spring will reach normal operating values after about 20 motion cycles. Only then is exact measurement of the inside diameter D1 (only at maximum  extension) and the outside diameter D2 possible.


The springs are maintenance-free. Depending on the degree of soiling, we recommend daily or weekly cleaning, followed by the application of a thin film of oil. Special oil spray can be supplied by us. Telescopic Springs should NEVER be greased!


Download Spring Specs (PDF)

All dimensions are in millimeters.

Type Code
Our itemized list gives all the technical data of our Telescopic Springs. These are combined to form our order numbers:

Relevant Resources

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