TM-9-2320-387-24 HMMWV Direct Support & General Support Maintenance Manual Volume 2 Download
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TM 9-2320-387-24-2 1 O-56. BODY REPAIR-(Cont’d) NOTE While drilling, hold drill at 90” angle to material surface. Avoid letting drill wobble, marking oblong holes. Avoid excessive pressure. Let drill bit do the cutting. Do not push drill through material. (d) Remove all burrs with a metal countersink or file. (e) Clean away all drill chips. Care must be taken to assure no chips are trapped between sheets of metal. (f) Apply sealing compound to hole and surrounding area. 5. Hole Countersinking. (a) (b) (cl NOTE Some rivet installations in the body require that rivet head be flush with the material surface. In these instances, countersunk or flush-head rivets are used. When using countersunk rivets, rivet holes must be countersunk with a tool having a 100” taper so rivet head will fit flush with surface. When using a hand-operated countersink, the hole must be tried with a rivet so the recess will not be too deep or too shallow. It is best to use a countersink with a stop on it so depth of countersink can be controlled. Typical countersinking dimensions for blind rivets are shown in table 10-3. The minimum sheet thickness that can be machined for 100” countersink rivets is given in table 10-4. Do not remove edge of hole on blind side of joint. Table 10-3. Countersinking Dimensions for 100” Countersunk Blind Rivets. COUNTERSINKING DIMENSIONS (100’) 4-a C Table 10-4. Minimum Sheet Gauge for 100” Machine Countersink. RIVET SIZE (INCH) 3132 If8 5132 3116 I/4 ‘* GAUGE. (INCH) 0.040 0.050 0.064 0.072 0.072 1o-94