Flex Drives

Speedograph Richfield

Synonymous with Quality Speed Products.

Flexible Drive Cables (Smith’s Industries Code ICD)

Speedograph Richfield has over 60 years experience of flex drive making ensuring you get the best from the best.

A flexible drive enables the indicator to be conveniently placed up to 6 metres (20 ft) away from the machine take off. Features include: tough, waterproof covering, steel outer for extra protection against crushing, rigid design for longitudinal strength and freedom from “wind up”, all flex drives are suitable for clockwise or anti-clockwise rotation and are lubricated for long life.

When designing the layout for a flexible drive run, the following principles should be followed to ensure smooth operation and long life:

Keep the flex drive as short as possible.

Try to keep to straight runs and avoid any sharp bends, if necessary use an angle drive.

  • Where bends are unavoidable they should not have a radius of less than 230 mm (9”) otherwise the life of the flex drive will be reduced and fluctuations may be induced in the tachometer reading.
  • Drives should be supported every 400 – 500 mm (15” – 18”) along their length to prevent sagging and wear.
  • We can produce any take off drive that you require.

The instrument end would have a 1.1/4” x 20 TPI Union Nut and 3.5 mm square drive (Smith’s Code LW).

Some of the more popular ones are:

Smith’s Code

Union Nut


S R Code


¾” x 26 TPI

.292” Key



7/8” x 18 TPI

3/16” Key



7/8” x 18 TPI

5/32” Key



¾” x 26 TPI

3/32” Spade


Whatever your application we can produce exactly what you want so Contact Us today.

Contact Us

Speedograph Richfield Automotive division

[Industrial Instruments] [Mechanical Tachometers] [Electrical Tachometers] [Drive systems] [Instrument Drives] [Accessories] [Flex Drives] [Service and repair] [Contact Us]