Flashcards
D.T
Flashcards do conjunto (12)
- 1Machine Screws-parallel sides, standard threads, usually carbon steel mass produced, can come with a variety of heads or tops. Most common countersunk and cheese heads.Countersunk-flush, cheese head-above. Also grub screws.Tightened by slot, Phillips and pozi-drive screwdriver.Or hexagonal Allen keys.
- 2Wood screws-classified by shape of head and length. Raised head similar to countersunk screw except that the head itself is slightly domed.Round headed screw designed to rest on top of surface. Pilot hole first. Wood-screws tapered. Sold by gauge and length.
- 3Rivets-making a permanent joint in metal. Solid rivets-manufactured from soft iron because they need to be ductile and easy to work as they have to be hammered into shape. Snap rivet-domed head.Pop rivets-aluminium and instead of being hammered into shape are fixed in place using a pop rivet gun.
- 4Spur gears-simple gearboxes, speeds can be +/-, direction of rotation can be changed.Bevel and Mitre-can have shafts at 90 degrees, different sizes of gear can change speeds, commonly seen on hand drills.
- 5Worm and Wheel-transmit force and motion through 90 degrees, reduction in rotational speed possible, used in food mixers.Rack and Pinion-used to change rotary motion into linear motion, used in pillar drills and car steering mechanism. Shape of gear tooth mathematical curve called an involute.
- 6Right-hand knife tool-used to face the left-hand edge or cut a shoulder to the left.Left-hand knife tool-used to face the right-hand edge or cut a shoulder to the right.
- 7Round nose tool-cut in any direction and produce radii.Parting off tool-moves at right angles into the work to sever material.
- 8Form tool-special profiles to cut specific shapes.Knurling tool-produce pattern or textured surface on the material.
- 9Boring tool-tool to enlarge existing hole when large drill unavailable or to produce a flat-bottomed hole.Weld-fusion joint, two pieces of metal melted together.
- 10Oxyacetylene welding-two gases mixed in gas torch, ignited, used as source of heat. Filler rod used to complete joint.Metal Inert gas welding-form of electric arc welding. arc struck between work and electrode, by electric current, used as heat source. Inert gas acts as an envelope to keep oxygen from joint. Prevents oxidation on joint and therefore helps to make the weld.
- 11Brazing-using spelter, 65% copper and 35% zinc, melting point of 875 degrees. Flux prevents oxidastion, plus breaks down surface tension on molten spelter, allows flow. Should be arranged on a refractory brick.Hard/silver soldering-capillary joint. Hard solder melting point 625 degrees to 800 degrees.
- 12offhand grinding-fixed to bench. sharpen chisels, etc.Rasp-wood only.Warding file-very small and thin designed for fitting in small slots , dreadnought files are for soft metals.File card used to clean out pieces of material that have been stuck in the teeth.
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- FlashCards sobre D.T , criado por george.steam em 01-06-2015.
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- george.steam
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