Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Unit 13 Fastening Metal

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Unit 13

Fastening Metal


Fastening Metals• Three ways to fasten metals together

– using fasteners (screws, bolts, and rivets)– soldering/brazing– welding

• Selecting the correct method depends on- the thickness of the metal- strength needed- appearance needed- cost


Drilling Holes in Metal

• Holes are needed to permit screws to pass through

• Usually made with high-speed twist drill

• If threads are needed, hole must be a very specific size


Other Methods

• Punching: faster than drilling; only on thin metal

• Threading: cut into the hole with a tap


Metal Fasteners

• Nuts and bolts

• Sheet metal screws

• Rivets


Solder

• Mixture of tin and lead

• Used to join thin metal, make electrical connections, and join copper tubing/pipe

• Most soldering done with 50-50 solder

• Water supply must be lead-free solder


Soldering Safety

• When using a propane torch– Wear goggles and insulated gloves

– Work area must be free of paper, grease, fuel, and other flammables

– Point torch away from you when lighting

– Use approved safety procedures and materials

– Place sheet metal behind pipes


Important Terms• Soldering/brazing: fastening metal by melting a second

metal between the pieces• Welding: melting metals together• High-speed drill: hardened for use in metal• Jobbers-length drill: longer length drill• Tap: a hardened, brittle, fluted tool used to cut threads

into a hole• Die: cuts threads onto a rod or bolt


Important Terms (continued)

• Tap and die set/screw plate: set of tools for making threads

• Taper, plug, and bottoming taps: tools used to tap threads inside a hole

• Bolt threads: straight; can be cut the entire length of a rod

• Pipe fittings: hollow connectors designed to attach to pipe



• Teflon tape/pipe joint compound: material used to seal the area between threads when used to deliver gases or liquids

• Rivet: fastening device held in place by flattening one or both ends

• Tinning: coating the tip of a soldering copper with solder

• Flux: material that removes tarnish or corrosion



• Hollow core solder: solder with flux inside• Soldering copper: tool used for soldering• Sal ammoniac: cube of special flux used to clean

soldering coppers• Sweating: the process of soldering copper pipe

into a fitting

Documents

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Unit 13 Fastening Metal