For material thicker than 1/8 inch, the remaining thickness is addressed by increasing amperage at what rate per 25% of remaining thickness?

• A. Increase by 1 amp per 25% of remaining thickness
• B. Increase by 0.5 amp per 10% of remaining thickness
• C. Increase by 2 amps per 50% of remaining thickness
• D. Decrease by 0.5 amp per 25% of remaining thickness

Answer: (A)

When welding thicker base metal, you must increase the heat input to maintain proper fusion and bead shape. The way this is done on the test is to raise amperage in proportion to how much thickness remains beyond a starting reference (1/8 inch). Specifically, you increase the current by about 1 amp for each 25% of the remaining thickness. This keeps the arc hot enough to penetrate deeper as the material gets thicker, without overdoing it.

For example, if the thickness beyond 1/8 inch amounts to a quarter inch, you would add about one amp. If it’s a half inch beyond 1/8 inch, you’d add about two amps. The other rate options don’t align with this practical adjustment rule, which is all about scaling heat input with the amount of extra thickness.