Sheath Materials
Supply and demand on the mineral insulated cable market comprise a vast array of sheath qualities with the main emphasis on materials suitable for certain applications and those with a historical basis. To limit this choice to an acceptable range as far as production and stock are concerned we are obliged, in particular with high grade stainless steels, to carry out a selective process for our standard production programme. A number of other sheath material qualities are available, and can be used for customer specials.
The following table and explanations are intended as an aid. By comparing the qualities available the customer is in a position to select the most suitable sheath material for his own purpose from the ISOMIL qualities available.
Common Sheath Materials
| Material No. | Short Description | AISI (USA) | BS (GB) | AFNOR (FR) | UNI (IT) |
| 1.4301 | (X5CrNi 18-9) | 304 | 304S | Z6CN 18-09 | X5CrNi 1810 |
| 1.4306 | (X5CrNi 19-11 ) | 304L | 304S | Z2CN 18-10 | X3CrNi 1811 |
| 1.4401 | (X5CrNiMo 18-10) | 316 | 316S | Z6CND 17-11 | X5CrNi MO1712 |
| 1.4404 | (X2CrNiMo 18-10) | 316L | 316S | Z2CND 17-12 | X2CrNiMo 1712 |
| 1.4541 | (X6CrNiTi 18-10) | 321 | 321S | Z6CNT 18-11 | X6CrNiTi 1811 |
| 1.4550 | (X6CrNiNb18-10) | 347S | Z6CNNb 18-11 | X6CrNiNb 1811 | |
| 1.4571 | (X6CrNiMoTi 17-12-2) | 316TI | 320 S31 | Z6CNDT 17-12 | X6CrNiMoTi 1712 |
| 1.4845 | (X12CrNi 25-21 ) | 310S | 310S | Z12CN 25-20 | X6CrNi 2521 |
| ASTM | |||||
| 2.4816 | Alloy 600 | 600 | NC15Fe | B163. 166-168 | |
| 2.4851 | Alloy 601 | 601 | |||
| 1.4876 | Alloy 800 | 800 | NA15 | Z10NG32-21 | |
| 2.4858 | Alloy 825 | 825 | NA16 | NFe 32C20DU | |
| Incotherm TG | Nicromil | 3072-3074 | |||
| Roy. Swed. | |||||
| 2.4951 | Nimonic 75 | HR 203, 504 | NC20T | MH. 05 | |
Composition and Physical Properties
(Composition of Sheath Material wt.-%)
| Material No. | Ni | Cr | C max. | Si max. | Mn max. | Fe | Mo* | Others** |
| 1.4301 | 8,0-10,5 | 17,0-20,0 | 0,07 | 1,0 | 2,0 | Rest | ||
| 1.4306 | 10,0-12,0 | 18,0-20,0 | 0,03 | 1,0 | 2,0 | Rest | ||
| 1.4401 | 10,5-13,5 | 16,5-18,5 | 0,07 | 1,0 | 2,0 | Rest | 2,0-2,5 | |
| 1.4404 | 10,0-13,0 | 16,5-18,5 | 0,03 | 1,0 | 2,0 | Rest | 2,0-2,5 | |
| 1.4541 | 9,0-12,0 | 17,0-19,0 | 0,08 | 1,0 | 2,0 | Rest | Ti > 5xC | |
| 1.4550 | 9,0-12,0 | 17,0-19,0 | 0,08 | 1,0 | 2,0 | Rest | Nb > 8xC | |
| 1.4571 | 10,5-13,5 | 16,5-18,5 | 0,08 | 1,0 | 2,0 | Rest | 2,0-2,5 | Ti > 5xC |
| 1.4845 | 19,0-22,0 | 24,0-26,0 | 0,08 | 1,0 | 2,0 | Rest | N < 0,11 | |
| 1.4876 | 30,0-34,0 | 19,0-23,0 | 0,12 | 1,0 | 2,0 | Rest | Ti und AI 0,15-0,60 | |
| 2.4858 | 38,0-46,0 | 19,5-23,5 | 0,05 | 0,5 | 1,0 | 2,5-3,5 | Ti 0,6-1,2 Cu 1,5-3,0 | |
| 2.4816 | >72,0 | 14,0-17,0 | 0,15 | 0,5 | 1,0 | 6,0-10,0 | ||
| 2.4851 | 58,0-63,0 | 21,0-25,0 | 0,10 | 0,5 | 1,0 | Ti < 0,5 AI 1,0-1,7 | ||
| Incotherm TG | 73,6 | 22,0 | 1,4 | 3,0 | ||||
| 2.4951 | Rest | 18,0-21,0 | 0,08-0,15 | 1,0 | 1,0 | <5,0 | Ti 0,2-0,6 | |
| *) Molybdenum can be used - depending of the alloy - to improve corrosion resistance to a number of acids and resistance to pitting. | ||||||||
| **) Niobium and Titanium bind the carbon (as carbide formers) thus preventing the formation of Cr carbides on the grain boundaries during welding which could lead to embrittlement in the welding zone. | ||||||||
