Fasteners Hardware They simplify manufacture They simplify repairs

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Fasteners & Hardware

Fasteners & Hardware

§ They simplify manufacture. § They simplify repairs. § They provide safety.

§ They simplify manufacture. § They simplify repairs. § They provide safety.

§ STRENGTH: Will it hold the loads and pressures? § SECURITY: Will it remain

§ STRENGTH: Will it hold the loads and pressures? § SECURITY: Will it remain attached? § COST: Realistic? § INSTALLATION: Appropriate for situation? § SKILL: Is specialized training needed? § EQUIPMENT: Is specialized equipment needed and available? § APPEARANCE: If the fastener shows, which kind looks best?

§ Simple & quick § May not result in the strongest of joints §

§ Simple & quick § May not result in the strongest of joints § Variety of shapes and sizes § Each type designed for a particular purpose § Drive nails at angles slanting toward or away from each other to get best holding power

“Mechanical devices for fastening things together. it penetrates only by being turned, as with

“Mechanical devices for fastening things together. it penetrates only by being turned, as with a screwdriver. ” § The most common types of screws are: t. Wood screws t. Sheet-metal t. Machine screws t. Set screws

§ Serve much the same purpose as a nail, but: § greater holding power

§ Serve much the same purpose as a nail, but: § greater holding power § easily removed and replaced. § neater in appearance and offer more decorative possibilities. § In addition to fastening pieces of wood together – the most common use of wood screws would be to anchor objects (hardware) to a wood surface.

§ Also called “Tapping Screws” or “Self-Threading Screws”. § Used to fasten light pieces

§ Also called “Tapping Screws” or “Self-Threading Screws”. § Used to fasten light pieces of metal together or to attach covers, panels and other light parts. § These screws have sharp threads that can cut their own grooves into metal. § Distinguishable from wood screws in that they are threaded all the way from the point to the head.

§ Used for the assembly of metal parts and usually are driven into “threaded”

§ Used for the assembly of metal parts and usually are driven into “threaded” holes rather than drawn tight with nuts. § there are many head designs to choose from. § Machine screw threads are also designated by the number of threads per inch, just like bolt threads: § A 6 -32 machine screw has a #6 body diameter and 32 threads per inch of length. § Most machine screws are fully threaded to the head.

§ Frequently used to hold a knob, collar, pulley or gear to a rotating

§ Frequently used to hold a knob, collar, pulley or gear to a rotating shaft. § There a variety of “head” or “point” styles, each best suited for its job. § Not an especially strong type of fastening – depend on friction and “shear” to hold parts together.

1. Type of head 2. Material made of 3. The length 4. The diameter

1. Type of head 2. Material made of 3. The length 4. The diameter

Screw Head “Styles” Screw Head “Shapes” Pan Head Flanged Hex Head Truss Head Hex

Screw Head “Styles” Screw Head “Shapes” Pan Head Flanged Hex Head Truss Head Hex Head

§ When exposed to “weather”, coatings offer more protection. § Steel Blued § Zinc

§ When exposed to “weather”, coatings offer more protection. § Steel Blued § Zinc Coated § Chromium § Galvanized § Nickel § Silver Plate § Gold Plate § Marine Applications § Stainless Steel § Aluminum § Copper § Brass § Bronze § Synthetic Materials (Plastic or Nylon)

Length • commonly range from ¼ inch to 4 inches. • Shorter or longer

Length • commonly range from ¼ inch to 4 inches. • Shorter or longer lengths are generally special order items. • Metric lengths are also available

Diameter • expressed by the “gauge” number or by the fraction of an inch.

Diameter • expressed by the “gauge” number or by the fraction of an inch. • metric diameters are expressed in mm

§ Diameters less than ¼ inch (6 mm) use gauge number. § Diameters greater

§ Diameters less than ¼ inch (6 mm) use gauge number. § Diameters greater than ¼ inch use fractions of an inch. § Wood screws are an exception to this rule in that they generally go up to a #20 gauge (21/64”).

§ Machine Bolts: § Square or hex head § Usually used in plain holes

§ Machine Bolts: § Square or hex head § Usually used in plain holes drilled through the parts being fastened. § Generally held in place with a nut. § Carriage Bolt: § Round headed bolt § Commonly used for fastening wood parts § Square neck under head § Generally held in place with a nut

§ Threads – External helical ribs on the body of a bolt. Usually a

§ Threads – External helical ribs on the body of a bolt. Usually a bolt “mates” with internal threads of a nut. § Threads are measured by counting the number per inch. (Metric threads are measured by the distance between threads – pitch – in mm) Thread gauges are available that match threads against those on the gauge.

§ have internal threads so that a bolt may screw into it. The threads

§ have internal threads so that a bolt may screw into it. The threads must match! § Threads per inch or distance between threads can be determined with a thread gauge just like bolt threads. § Nuts have three important dimensions: § Thickness § Distance across the flats § Inside diameter (same as that of the bolt with which it is to be used).

§ They are paired with and matched to bolts and nuts

§ They are paired with and matched to bolts and nuts