Metal leg, able to be pressed into place (4-2)
I believe the answer is:
iron-on
'able to be pressed into place' is the definition.
(able to be ironed on)
'metal leg' is the wordplay.
'metal' becomes 'iron' (iron is a metal).
'leg' becomes 'on' (cricket term, fielding positions).
'iron'+'on'='IRON-ON'
(Other definitions for iron-on that I've seen before include "Designed to be attached by heat and pressing" , "ready to be transferred under pressure" .)