TM-9-2320-280-34 HMMWV Direct Support & General Support Maintenance Manual Download
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TM 9-2320-280-34 d. Rivet Hole Drilling. 1. Center punch all new rivet locations. Center punch mark must be large enough to prevent drill from slipping out of position, yet it must not dent the surface of the material. To prevent denting, place a bucking bar behind material during punching. 2. Make sure drill is the correct size (tables 22-1 and 22-2) and point is properly ground. A no. 10 drill is used to install standard 3/16-inch blind rivets. Table 22-1. Drill Sizes for Solid Shank Rivets RIVET DRILL DIAMETER DRILL SIZE DIAMETER (INCH) (INCH) 1/16 #51 0.0670 3/32 #41 0.0960 1/8 #30 0.1285 5/32 #21 0.1590 3/16 #10 0.1910 1/4 F 0.2570 5/16 P 0.3230 318 W 0.3860 Table 22-2. Drill Sizes for Blind Rivets NOMINAL DIAMETER (INCH) OVERSIZE DIAMETER (INCH) RIVET DRILL RIVET DRILL DIAMETER SIZE MINIMUM MAXIMUM DIAMETER SIZE MINIMUM MAXIMUM 1/8 #30 0.129 0.132 1/8 #27 0.143 0.146 5132 #20 0.160 0.164 5/32 #16 0.176 0.180 3116 #10 0.192 0.196 3/16 #5 0.205 0.209 3. Place drill in center mark for new rivet locations, or align drill with old hole when replacing old rivets with oversize rivets. When using a power drill, give the bit a few turns with fingers before starting motor. This will help assure that drill does not jump out of position when motor is started. NOTE While drilling, hold drill at 90 degree angle to material surface. Avoid letting drill wobble, making oblong holes. ·Avoid excessive pressure. Let drill bit do the cutting. Do not push drill through material. 4. Remove all burrs with a metal countersink or file. 5. Clean away all drill chips. Care must be taken to assure that no chips are trapped between sheets of metal. 6. Apply sealing compound (Appendix B, Item 47) to hole and surrounding area. 22-8