Tech Tip #3: Metric to Fractional Conversion

Dr. Diesel
Written by Dr. Diesel

Helpful guide to the Metric to Fractional Interchange with today’s most popular sizes.

This winter are you planning on assembling an on-board tool kit for your Perkins marine engine? Or maybe a field service kit for your Deutz in a screening plant? Here’s a way to save time, weight, space, and money: use selected standard sizes and metric size sockets interchangeably.

Listed below are common interchanges that are safe to use and will insure a snug fit. As a precaution, try not to exceed 5 thousandths difference in size to avoid rounded-off head bolts.

Standard Fractional Size

Metric Size

Difference in Thousandths

15/64

6

.002

5/16

8

.003

7/16

11

.004

5/8

16

.005

3/4

19

.006

Dr. Diesel
Written by Dr. Diesel
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