Table 1 Vickers hardness mean and standard deviation.

1

Strip 1# operating side

175.1

22.9

2

Strip 1# central

167.5

17.3

3

Strip 1# drive side

171.4

18.8

4

Strip 2# operating side

182

19.5

5

Strip 2# central

175.3

17

6

Strip 2# drive side

180.9

16.9