When building or servicing engines and other machinery, gaps and tolerances must be accurately measured. Your measurements can be spot on thanks to the range of feeler gauges from ToolPRO. The ToolPRO combination feeler gauge is the most comprehensive in the range, with 30 steel blades providing measurement in fractions of millimetres and inches and a further 6 brass blades for use around magnetic components. Taking a measurement using a feeler gauge is easy. First, ensure that the gap to be measured is free of dirt or greasy build up. Make sure that the feeler gauges are clean and well-oiled also. Start by finding the closest possible blade that will fit in the gap. If the blade moves too freely within the gap, stack multiple blades until a snug fit is obtained. Feeling for resistance is key here. The proper resistance can be likened to pulling a sheet of paper from under a magazine, or peeling packing tape off a roll. Now, add up the total thickness of all blades used and check this against a workshop manual to determine if your part is within specification.