After you cut the tubing, remove all burrs and sharp edges from inside and outside of tube (fig. 6-7) with deburring tools. Clean out tubing. Make sure that no foreign particles remain. A Permaswage deburring tool may be used to remove burrs from inside of tubing. Select deburring tool and stem subassembly (fig. 6-8) required for the size of tubing to be deburred. Lubricate the sliding collar on the end of elastic plug with light oil if necessary to get free movement. Engage threads and insert stem subassembly into cutter end of deburring tool by depressing the plunger, and screw stem subassembly into plunger until it bottoms and fingertightens. Check assembly deburring tool. Depress plunger and the plug. Outside diameter should be reduced to the same diameter as metal support collar on either end of elastic plug. Release plunger. Two distinct circum-ferential bumps will appear on elastic plug beyond outside diameter of metal support collars. Check the tube end for squareness. Check the elastic plug for wear and cleanliness. Replace worn or damaged elastic plug. Clean and lightly lubricate elastic plug with lubricant compatible to hydraulic fluid to be used

Figure 6-8.Permaswage deburring foot (typical).

in tubing. Grasp deburring tool in one hand with two fingers on collar and thumb on plunger. Depress plunger with thumb and insert elastic plug into tube opening until cutter is about 1/8 inch from tube end. If the plug fit is tight due to a large burr on ID of the tube, slowly rotate the plunger end of tool while gently pushing tool into the tube end. Release plunger to allow elastic plug to expand and seal tube opening to prevent chips from entering. Hold tube end and rotate knurled body of deburring tool in a clockwise direction while applying pressure to cutter.

Continue rotating tool until resistance decreases, indicating all burrs have been removed from tube ID. You should avoid excessive deburring, which can cause too deep a chamfer on tube ID. The chamfer should not exceed one-half wall thickness of tubing. Relax pressure and rotate deburring tool several times to produce a smooth surface. Without depressing plunger, ease deburring tool from tube until the first bulge of elastic plug is exposed. Wipe off the tube end and plug. Check the tube end to see if it is completely deburred. If tube end appears saticfactory, without depressing plunger, remove deburring tool from tube. If tube end is not completely deburred, without depressing plunger, push deburring tool back into the tube and repeat all the steps.