Small Hole Gages These small hole gages are well balanced tools that are ideal for accurately measuring small holes, slots, grooves, and recesses in all kinds of work. They all feature: • Hardened-ball measuring surface with two-point contact • Radius on each gage is less than the minimum diameter to be measured, which provides the two-point contact necessary for maximum accuracy • Smooth, sensitive adjustment for better feel, giving more accurate measurements • The adjustment of the gage beyond their range is restricted by a safety stop that prevents breakage Accurate measurements are obtained by slightly "rocking" these gages in the hole to be measured. This will guarantee contact at the true diameter. The final size is then obtained by measuring over the ball contacts with a micrometer. Small Hole Gages 829 Small Hole Gages .125-.500"/3.2-12.7MM These full-ball gages are used for general work. 830 Small Hole Gages .125-.500"/3.2-12.7MM These gages are exactly the same as the 831 Small Hole Gage except that all gages are only 2" (50mm) long, making them convenient to use in close quarters. 831 Small Hole Gages .125-.500"/3.2-12.7MM These gages are exactly the same as the 829 Hole Gage except that the gaging surface is a half-ball with a flat bottom. This permits use in even the most shallow holes, slots, and recesses. Gaging Pt. Cat. 829 Cat. 831 829 Small Hole Gages Cat. No. EDP Range Approx. Length in mm in mm 829A 53070 .125-.200 3.2-5.1 2-7/8 75 829B 53071 .200-.300 5.1-7.6 3 80 829C 53072 .300-.400 7.6-10.2 3-3/8 85 829D 53073 .400-.500 10.2-12.7 3-1/2 90 829 Small Hole Gage Sets Cat. No. EDP Description S829EZ 53074 Set of 4 in case 830 Small Hole Gages Cat. No. EDP Range Approx. Length in mm in mm 830A 53076 .125-.150 3.2-3.8 2 50 830B 53077 .150-.200 3.8-5.1 830C 53078 .200-.300 5.1-7.6 830D 53079 .300-.400 7.6-10.2 830E 53080 .400-.500 10.2-12.7 830 Small Hole Gage Sets Cat. No. EDP Description S830FZ 53081 Set of 5 in case 831 Small Hole Gages Cat. No. EDP Range Approx. Length in mm in mm 831A 53083 .125-.200 3.2-5.1 2-13/16 70 831B 53084 .200-.300 5.1-7.6 3-1/8 80 831C 53085 .300-.400 7.6-10.2 3-3/8 85 831D 53086 .400-.500 10.2-12.7 3-1/2 90 831 Small Hole Gage Sets Cat. No. EDP Description S831EZ 53087 Set of 4 in case S830 S830EZ S829 S829EZ S831 S831EZ 320 H ole G ages and S lot G ages