Metal Preperation

Question 1

What is the fastest preparation method for
straight weld joints?
a. plasma cutting
b. air carbon arc
c. shearing
d. nibbling

Answer 1

c. shearing

Question 2

Which abrasive grit size would be used for
finishing a joint preparation?
a. 24-40
b. 50-80
c. 100-150
d. 180-240

Answer 2

c. 100-150

Question 3

How is the length of a file defined?
a. from heel to heel
b. from heel to tang
c. from heel to taper
d. from heel to tip

Answer 3

d. from heel to tip

Question 4

Why are single cut files only used in one direction?
a. the teeth are stripped off on the
backward stroke
b. the curved tooth smears on the
backward stroke
c. the teeth become clogged on the
backward stroke
d. the backward stroke only removes
half the material

Answer 4

a. the teeth are stripped off on the
backward stroke

Question 5

Why would you preheat before oxyfuel gas cutting?
a. to remove moisture
b. to prevent warping
c. to prevent hardening
d. to avoid cracking

Answer 5

d. to avoid cracking

Question 6

What is the best fuel gas for cutting rusty steel?
a. propane
b. natural gas
c. acetylene
d. acetone

Answer 6

c. acetylene

Question 7

Why can metals like austenitic stainless steels not be cut by the oxyfuel gas process?
a. too much free hydrogen in the flame
b. chromium oxide prevents the burning
c. thermal conductivity is too high
d. excessive hardening of the HAZ

Answer 7

b. chromium oxide prevents the burning

Question 8

If there is a fuel gas leak, which gas would rise
and collect in the upper part of a confined space,
creating an explosion hazard?
a. acetylene
b. propane
c. helium
d. MAPP

Answer 8

a. acetylene

Question 9

Cutting tip size is selected on the basis of:
a. material type
b. material thickness
c. fuel gas
d. torch design

Answer 9

b. material thickness

Question 10

Why is a smaller tip used rather than turning a
torch down too much when cutting thin material?
a. too much heat enters the material
b. kerf cracking can be produced
c. to prevent burnback into the torch
d. to expel the oxidized metal

Answer 10

c. to prevent burnback into the torch

Question 11

The bottom edge of an OFG cut is very rough and
irregular. What is the likely cause?
a. excess acetylene
b. travel too slow
c. excess oxygen
d. too close to the work

Answer 11

b. travel too slow

Question 12

Plasma cutting uses what mode of process
operation?
a. constant voltage
b. transferred arc
c. pulsed transfer
d. single beam

Answer 12

b. transferred arc