Tools • Textbook • Machining Fundamentals, John R. Walker, Goodheart-Willcox Company, Tinley Park IL (2004). $60 new, $35 used from Amazon. pp. 55-182. (Remainder is excellent, but not to be covered here.) • Other sources • McMaster-Carr catalog • Grainger catalog
Tools Definition: what is a “tool” 1. an implement, esp. one held in the hand, as a hammer, saw, or file, for performing or facilitating mechanical operations. 2. any instrument of manual operation. 3. the cutting or machining part of a lathe, planer, drill, or similar machine. 4. the machine itself; a machine tool. 5. anything used as a means of accomplishing a task or purpose: “Education is a tool for success.” 6. a person manipulated by another for the latter's own ends; cat's-paw. [???—Matt] [stolen from dictionary.com] “Things that you use to get stuff done.” A Matt original.
Etiquette/philosophy • If you use a tool more than a half dozen times, quit borrowing it and buy your own. It will save you time in the long run. • Always use the proper tool for the job. It’s not true that the only tools you need are a hammer, screwdriver and vise grips! • What is a hammer? • What is a screwdriver? • What are vise grips?
Measuring tools • What are the tolerances of the job you are doing? Can you pace off the distance or do you need an AFM to do the measurement? (Remember the concept of the sanity check?) • Never over-specify tolerances • Rulers and straightedges • Functions of rulers and straightedges • Rulers make great straightedges! • For greater lengths use a piece of angle iron, channel... • The 4' ruler is a great tool • So is the “15 inch foot rule” ubiquitous in the Department • Tape measures: avoid using the end for critical measurements, but be careful to do the math to correct for the fact that you are not starting your measurement at zero!
Measuring tools • Calipers • Dial • Advantage: easier to read, especially for old eyes • Vernier: how to read a vernier. • The underlying theory. • Advantage: both “APS” and metric on one instrument • Digital also
Measuring tools • Micrometers • Analog • Digital • Outside • Inside • Height gages and indicators: how to tell if your surface is flat • Squares • Machinist’s • Combination (triple combination) • Framing
Screws • Terminology • A screw is a shaft with a helical groove or thread formed on its surface and provision at one end to turn the screw. Its main uses are as a threaded fastener used to hold objects together, and as a simple machine used to translate torque into linear force. Wikipedia (The Wikipedia entry for “screw” is excellent! • Machine screws • Wood screws • Sheet metal screws; self-tapping screws • Head types • Flat, Round, pan, hex, socket • SAE (“APS”) terminology: 1/4-20 and 10-32 • first number is original shaft diameter (if a fraction of an inch) or, for a whole number, related to diameter by d = 0.060” + (# * 0.013”) • second is number of threads per inch • Metric diameters and thread pitches: coarse and fine threads • Wood screws and grabbers and the “screw shooter”
Accessories for Screws • Washers • Flat, lock, star...when to use them • Anchors and inserts • When and where to use them • Studs for concrete: epoxy makes them even meaner!
Non-Threaded Fasteners • Pins • Drift • Roll • Dowel • Taper • Nails • Staples, etc
Accessories • The Brookstone Screw Chek’r • Nothing but a plate full of tapped holes with sizes attached so you know what size of screw you have in your hand. • The Elemoto Screw Selector. • An old-fashioned cardboard “slide rule” that gives you every dimension imaginable on screws, nuts, washers, etc., specifically including the size of drill you use prior to tapping a hole.
Taps and DiesThe miracle of the Gun tap • Taps • Used to thread holes into material for inserting a screw • Use a reference to determine hole size to drill for your tap; this is not an opportunity for creativity! • Always use lubricant when tapping: Boelube • Use minimum torque • Reverse often to clean out the threads you are making • Two-fluted Gun taps cut amazingly clean threads • Plug and bottoming taps • Dies • Used on rod to “make your own screw”
More on Taps from Wikipedia • During operation, it is necessary with a hand tap to periodically reverse rotation to break the chip formed during the cutting process, thus preventing an effect called "crowding" that may cause breakage. Periodic reversing is usually not practical when power tapping is involved, and thus has led to the development of taps suitable for continuous rotation in the cutting direction. • The most common type of power driven tap is the "spiral point" plug tap (also referred to as a "gun tap"), whose cutting edges are angularly displaced relative to the tap centerline. This feature causes the tap to continuously break the chip and eject it into the flutes, preventing crowding. Another version of the spiral point plug tap is the spiral flute tap, whose flutes resemble those of a twist drill. Spiral flute taps are widely used in high speed, automatic tapping operations due to their ability to work well in blind holes.
Lubricants for Tapping • The use of a suitable lubricant is essential with most tapping and reaming operations [and only slightly less so for drilling]. Recommended lubricants for some common materials are as follows: • Carbon steel • Petroleum-based or synthetic cutting oil. Boelube! • Alloy steel • Petroleum-based cutting oil mixed with a small amount (approximately 10%) of kerosene or mineral spirits. This mixture is also suitable for use with stainless steel. • Cast iron • No lubricant. An air blast should be used to clear chips. • Aluminium • Kerosene or mineral spirits mixed with a small amount (15-25%) of petroleum-based cutting oil. Other oils also work, including WD-40, 3-In-One Oil, and mineral oil. • Brass • Kerosene or mineral spirits. • Bronze • Kerosene or mineral spirits mixed with a small amount (10-15%) of petroleum-based cutting oil.
Drills • Definition • Something used to make holes • Ambiguously refers to the tool and its energy source • Drill motors (the energy source) • Reversible • Variable speed • Hammer...the Hilti • Corded and cordless • Drill presses (“mechanical advantage”) • Magnetic base drill press • Chucks • Keyed • Keyless chucks
Drill bits • Fractional, letter and number • Metric • Pilot holes • Often the center of a large bit does not cut • Large drills are very difficult to start where you want • Center drills • The concept of deburring • Countersinks • Single flute • Others • Carbide drill bits for concrete • Hole saws • Knockout punches
Box and Socket Wrenches(At the Top of the Hierarchy) • 6-point are stronger and less likely to strip the corners off the nut/bolt head. • 12-point give you finer gradations to work in tighter spots • Ratchets and breaker bars • 1/4" to 1" drive • Extensions • U-joints (Universal) • Lug wrenches • Never use an air wrench to put the wheels on your car: you may not have one when you need to take it off!
Wrenches cont’d • Open end wrenches (combination wrenches) • “Crescent” (adjustable) wrenches • Slip-joint pliers (Not a wrench, but can be misused for one!) • Vise grips (Not a wrench, but can be misused for one!) • Pipe wrenches (except when used on pipes) • Strap wrenches • The “cheater”, a piece of pipe that goes over the handle of the wrench and extends it: the existential definition of torque • The torque wrench and torque specifications • The act of stripping threads • When the screw gets tighter and tighter, then all of sudden easier to turn, you have a problem. • Either stop immediately or replace what you just ruined. • The “easyout”: great concept, works reasonably well for bigger bolts; impossible for really small ones, where you really need it! • Hex keys, “Allen “ wrenches • Torx wrenches
Other Wrenches • Open end wrenches (combination wrenches) • Ford and monkey wrenches (You are unlikely to ever see one.) Ford wrench
Galling • “Galling is a cold welding phenomenon which can occur when uncoated stainless steel or aluminium alloy parts, such as the threads of nuts and bolts, are forced together. These materials owe their corrosion resistance to the ease with which they passivate, forming a thin protective oxide layer. The friction scrapes off this oxide layer from the surface asperities* and exposes clean reactive metal. If the mating parts are of a sufficiently similar material, no additional activation energy is needed to cold weld them together. • Stainless is most susceptible to galling, copper next, then aluminum. Never occurs with dissimilar metals.
Galling, cont’d • *[asAperAiAty (-spr-t) • n. pl. asAperAiAties • 1. A. Roughness or harshness, as of surface, sound, or climate: the asperity of northern winters. B. Severity; rigor. • 2. A slight projection from a surface; a point or bump. • 3. Harshness of manner; ill temper or irritability.] • Galling can occur even if the parts are brought together slowly • It is prevented by the presence of grease or surface coatings, even if the surface coatings increase friction. • It does not occur when joining dissimilar materials (for example threading 18-8 stainless into 17-4 stainless) even though both of those materials are susceptible to galling. • Galling does not occur on carbon steel.
Leonard’s Famous Experience with Galling • 1 each 12 KV, .25" Single Conductor (185A) feedthrough w / 1" baseplate flange • $164.00 each • Stainless nut galled stainless feedthrough • In addition to being corrosion-resistant, stainless is very strong • Nut had to be cut off with abrasive wheel!
Screwdrivers • The utility of a screwdriver is directly proportional to the size (diameter) of the handle; cheap little screwdrivers are nearly worthless • Flat • Blade should fit the slot as tightly as possible • Hollow ground vs straight taper • Phillips • The cheap ones are worthless because they are too pointy! • Sizes: 1, 2, 3, 4 • Screw-holding • Split • Clip • Offset • Impact screwdrivers • Torx drivers • Nut drivers
Hammers and Mallets • Claw/ripping/framing • Ball pein • “Engineer”/sledge • Dead soft/mallets Sledge Hammer
Pliers, etc • Lineman’s pliers • Cutting pliers • Parallel jaw pliers • Slip joint pliers • Channellocks (tongue and groove pliers) • Vise grips: “World’s mightiest hand tool” • Needle nose pliers • Wire strippers
Grinding, Abrading and Sharpening • Applications • Material removal • Smoothing • Files • Terminology • “Coarse”, Bastard”, “Second cut” and “Smooth” refer to coarseness of file • “Cut” refers to number of teeth per inch of length. Appears to vary with file length! • Shapes: Flat, round, half-round, square… • File cards • Rasps for wood
“Sandpaper” (Wiki) • Materials used for the abrading particles are: • flint — no longer commonly used • garnet — commonly used in woodworking • emery — commonly used to abrade or polish metal • aluminium oxide — perhaps most common in widest variety of grits; can be used on metal (i.e. body shops) or wood • silicon carbide — available in very coarse grits all the way through to microgrits, common in wet applications • alumina-zirconia — (an aluminium oxide - zirconium oxide alloy), used for machine grinding applications • chromium oxide — used in extremely fine micron grit (micrometre level) papers • ceramic aluminum oxide — used in high pressure applications, commonly known as Cubitron by 3M, who invented sol gel ceramic grains.
Abrasives cont’d • “Sandpaper” • Historically abrasive was made from sand glued to paper • If still available, vastly inferior • Aluminum oxide and garnet are modern replacements • SiC paper • “Wet or dry” • Worth the extra money • Grit sizes: 60 to 1500 • Emery cloth • “For rust and corrosion removal and metal sanding. Cloth backed. “ • Scotch-brite • “Scotch-Brite™ Hand Pads are the alternative to steel wool that will never rust. Impregnated with aluminum oxide abrasive for fast cut, the durable, 3-dimensional nylon web resists tearing, shredding, and loading for long life.”
Abrasives cont’d • Belt and disk sanders • Stationary • Portable • Grinders • Stationary • Portable • Wire brushes • Hand • Stationary, electric
Saws • Hack saws for metal • Saws for wood • Crosscut • Rip • Keyhole (sheetrock, too!) • Coping • Power saws • Portable • “Skilsaw”, a.k.a. “Finger remover” • Jig saw/Scroll saw • “Sawzall” • Stationary • Table saw (wood) • Radial arm (wood) • Band saw (wood OR metal...but not both!). The Marvel • Panel saw • “Chop saw” (cutoff saw; miter saw) Miter box! • Saw blades • Steel for wood, plastic, other soft materials • [Tungsten] Carbide for fine finishes on wood
Band Saw Teeth Metal: finer Wood: coarser
Other Cutting Tools • Tubing cutter/pipe cutter • De-burring tools • “Tinsnips” • Boltcutters • Knockout punches • Utility knives
More Cutting Tools • Routers for wood • Cut edges • Cut slots • Cut dovetails • Use guide wherever possible
Chisels • Chisels • Wood • Extremely sharp • Always chisel away from yourself! • Errors can be fatal! • Metal: When to use them • “Floor chisels”
Center punches, drifts... • Failure to center punch steel or other hard metals will give you about a 10% probability of getting the hole where you wanted it. • Following the center punch with a center drill will give you a 100% probability of getting the hole where you wanted it • If you can find an “automatic center punch” that actually works, I’ll buy it from you! • Use a scribe to mark metals with accuracy much greater than you could get from a pencil.
Truly miscellaneous stuff • Carpenter’s pencils • Scribes (Dychem “paint”) • Levels • Come in various lengths • Use whenever you want two things at the same elevation..like pictures, shelves! • Wire strippers • The “grabber” tool
Vises Woodworking Vise Machinist Vise
Truly miscellaneous stuff • Clamps • Bar • Pipe • C-clamps • Handscrews • Putty knives. • Putty? • Sheetrock compound • Scraper • Inspection mirror
Where to buy quality tools • There is no worse investment than a cheap tool. “Quality has no regrets.” • Quality brands • This isn’t easy: almost everyone makes good tools and cheap tools and they are not easy to differentiate. • Quality also changes with time. • Delta and Powermatic stationary power tools • Milwaukee, Makita, DeWALT, Hitachi, Bosch, Black and Decker, Porter Cable • You can get amazingly good bargains at Harbor Freight. You will rarely get very high quality. • Klein, Craftsman • Avoid • Stanley Handyman and Sears Champion; Home Depot off-brands like Husky