501 - 508

C n2 + 3T

Esslingen (Saronno Works, Italy)

1892-94

No. 502, 503, 505 and 506 to SEK as Δζ 111 - 114 respectively

509 - 510

1' C n2 + 3T

Maffei

1908

To SEK as Εβ 231 – 232

521 - 523

1' C h2 + 3T

Borsig

1912

To SEK as Εγ 241 – 243