Self-Centering Accuracy: Designed with a dual-pivot, self-centering mechanism, these bore gauges automatically align to the exact center of the bore. This minimizes operator error, helps prevent off-center readings, and delivers the precise internal diameter data you need for accurate machining and repairs. Workshop-Tough Construction: Built from chrome-plated hardened steel, this telescoping bore gauge T-gage set resists abrasion and for long-term durability. The robust construction stands up to daily use in professional workshops, expanding their service life well beyond standard carbon steel tools. Full Range Coverage: This 6-piece T bore hole gauges set offers a measuring range from 5/16" to 6", giving you the versatility needed for engine cylinders, pipe fittings, bushings and machinery slots. Always have the right gauge on hand to avoid missed sizes and extra tool purchases. Smooth Sliding Action: Each telescoping gauge features finely polished rods and balanced spring tension that provide consistently smooth sliding performance. The telescopic extend and retract without sticking, reducing the need for frequent lubrication and speeding up repetitive measurements. Easy Four-Step Measuring: Insert the gauge into the bore, gently expand and rotate to find the true diameter, lock the knurled knob, then read with your micrometer or caliper. This simple four-step process allows both beginners and professionals to complete measurements quickly and consistently., Manufacturer: CTRLZS