William Hughes, manufacturer of
springs, bent wire-forms and
assemblies, is responding to industry
demand for single source solutions
with new ‘added-value’ services.

Among the new controlled processes
are steel and glass shot peening,
ultrasonic cleaning and tensile
testing to national standards such as
AMS (Aerospace Materials
Specifications).

Steel shot peening involves firing
or blasting a known size of cut wire
shot at a component, such as a spring,
to create compressive residual stress
layers that modify its mechanical
properties. For many tasks, the aim is
increased spring longevity. The
process is defined by quality, size and
intensity of shot, with established
measurement techniques used to
calculate how much stress is delivered.

After every eight machine working
hours, the size of the shot is checked
using a sieve shaker with different
mesh sizes to ensure the shot size is
correct. Visual screening under
magnification checks shot quality,
confirming it to be round and
without sharp edges. Other tests
include arc rise tests, using an Almen
strip to measure shot intensity, and
coverage testing.

The company also offers shot
peening using glass, a finer and
smaller media, that allows shot
peening without contaminating
component surfaces.