The British engineering industry experienced extreme production and employment pressures during the rearmament period that preceded the Second World War and in the early war years. Did it react by placing a greater emphasis on incentive-compatible payment methods? This paper examines the relative employment and wage effects on pieceworkers and timeworkers. Empirical work is based on detailed firm-level payroll data produced by the Engineering Employers Federation covering the period 1935 to 1942. The paper investigates the effects of war on piecework and timework in relation to (a) labour market arguments concerning substitution between payment methods, (b) piece rate/time rate adjustments to changes in product demand, (c) relative changes in employment and hours, and (d) relative changes in hourly and weekly pay.