A mechanical crew was engaged in removal of bolts from a flange as part of commissioning and de-spading activities. Whilst one of the crew members was hammering a spanner to remove bolts, a small splinter from the hammer cut through his cotton glove and hit his right index finger. This caused a minor superficial scratch injury on the finger. First Aid was given at site clinic and later he was diagnosed with partial tear on his right index finger extensor tendon which required a surgical repair.