C-2 Portable Power Tools Flashcards
Powder-actuated tools
use gunpowder to fire a fastener int either lumber or wood
Low - Velocity powder actuated tool
contains a “captive piston” meaning when the cartridge is fired, the force of the explosion acts first on the piston then fires the fastener to drive into meterial
safety features of LV tools
- captive piston
- built in device that prevents device from firing
- two distinct sequential actions required before tool can be fired
- method for verifying the power level
High Velocity tools
Direct acting tools they have no pistons and the fastening pins travel at speeds of 150-460 feet per second
Methods of Propulsion
- impact
- contact
- co-acting
Impact
type of fastener
gap between piston and fastener. fastener is against the work surface. tool is fired and piston travels down barrel to strike fastener
Contact
piston is in contact with fastener which then is in contact with work serface
co- acting
piston and fastener are not in contact with work surface
- piston and fastener reach certain speed before hitting work surface
Threaded
Bolting an object after a fastener has been driven
headed
for fastening an object to concrete or steel
eyelet
for holding lightweight objects such as suspended ceiling
Center Punch test
used to determine if a material is suitable for fastening with a powder actuated fastener.
try and punch fastener into material should make distinct dent
Minimum thickness of concrete for fastner
must be three times the penetration of fastener
- must be 75mm from edge of concrete
- do not fasten on joints
- spaced more then 3 inches
Spalling
when fastener blows out bits of concrete from point of entry
how to prevent spalling
use washer
- reduce shank diameter of fastener
- reduce shank length of fastener
- reduce cartridge strength
things to consider when fastening to steel
- must be at least 50mm or (2”) away from weld or joint
- must be at least 13mm (1/2”) away from edge of steel
- fasteners should be installed 1 inch apart
Gas Powered chainsaw
- most common
- portable
disadvantages is fumes
Electric powered Chainsaw
sometimes used in enclosed spaces where fumes are to hazardous. not as powerful as gas saws
Battery powered chainsaw
- use large rechargeable batteries 40v
- can be used when no electric power is available
Pneumatic chainsaw
air driven chainsaw that requires an air compressor. common in bridgework
Components of chainsaw
starter throttle lockout throttle fueltank chain oil tank bucking spike chain brake
Kickback
occurs when rotating chain momentarily hangs up on an obstruction and throws saw back on user
Chain cuts
chain still spins after finger is let off throttle keep eyes peeled and stay vigilant