- Patterns drawn straight onto the metal is known as simple pattern development ? true or false
true
Patterns are developed straight onto the proper cut size of metal with openings and allowances? true or false
true
True lengths of the surface are drawn on
plan and elevation views
- Round elbows are examples of parallel development
true
All sides that meet at an apex or common point are
radial line development
- Triangulation is used when patterns are irregular shaped object ( square to round and offset 90 are examples )
true
- Rollation developement is a example of a short cut method of pattern developement
true
When speed is a factor its fast and easy to make , funnels and round reducers are examples
rollation developement
- When you start a layout you only require the finish dimensions
true
Three measurements are required for rectangle pattern
width ,depth , length
two measurements are needed for round patterns
diameter and lenght
- Duct connections vary from each shop
true
- Duct connections vary from each shop
true
- S- cleat is “1” and the drive is “1 1/8”
true
- Slip and drive require 1/2 allowance to be added and standing drive(cp) requires two allowances
true
- Hammer lock ( tap in ) requires three allowances
true
Butt seam is usually heavier gauge and mostly
welded
Lap seams depend on whats going to fasten them together
( spot welded or rivets )
- Pitsburgelock is the most common lock used in the trade 1/4 male on straight 3/16 on a radius and female of “1
true
- Pitsburgelock is usually on the short part of the duct
true
Button lock is used on lighter material for
round and rectangular duct
- Acme lock is a double hook with a offset
true
When adding duct connections
add 1/2 for the slip and drive from the finish line on the shorter side of the fitting
