Technical Resources

We have gathered together a number of technical resources for use as reference on electrical projects.

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501/421 Hazardous Area Cable Gland

Flameproof Exd & Increased Safety Exe Dual Certified ATEX / IECEx

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The 501/421 cable gland provides a seal on the outer cable sheath and is intended for use on non-armoured elastomer and plastic insulated cables. The cable gland is dual certified Exd and Exe and is suitable for installation in Zone 1 (21) and Zone 2 (22) hazardous areas.

501/421 Hazardous Area Cable Gland

Cable Gland Selection Table

Entry Thread Size CCable Acceptance Details'G'Hexagon Dimensions
MetricNPT *
Standard or
Outer Sheath 'B'Across
Standard SealAlternative Seal
OsM20² ½"
OM20² ½"7.511.923.824.026.5
AM20¾" or ½"
BM251" or ¾"
CM321¼" or 1"19.026.515.521.
C2M401½" or 1¼"25.032.522.028.029.555.060.6
DM502" or 1½"31.544.4 / 42.3² 27.534.80.465.070.8
EM632½" or 2"42.556.3 / 54.3² 39.046.538.280.088.0
FM753" or 2½"54.568.2 / 65.3² 48.558.340.595.0104.0

All dimensions in millimeters (except * where dimensions are in inches). 2K – F size metric entry threads are 1.5mm pitch as standard, 15mm length of thread. For G size glands and above, a 2mm pitch is supplied as standard, 20mm length of thread (1.5mm pitch with 15mm length of thread can be supplied) please specify when ordering.

Smaller value is applicable when selecting reduced NPT entry option.
² Sizes Os and O are available with an M16 thread size. For O size with M16 thread, the maximum cable outer sheath diameter is 10.9mm

Technical Data

  • Flameproof Exd and Increased Safety Exe II 2 GD ExtD A21.
  • Certificate No’s: Baseefa06ATEX0056X and IECEx BAS 06.0013X.
  • Suitable for use in Zone 1, Zone 2, Zone 21, Zone 22 and in Gas Groups IIA, IIB and IIC.
  • Construction and Test Standards: IEC/EN 60079-0, IEC/EN 60079-1, IEC/EN 60079-7, IEC/EN 61241-0 and IEC/EN 61241-1.
  • Ingress Protection: IP66, IP67 and IP 68 (30 metres for 7 days) to IEC/EN 60529 and NEMA 4X.
  • Deluge Protection to DTS01.
  • Operating Temperature Range: -60°C to +100°C.
  • Assembly Instruction Sheet: AI 307.

Alternative certification options available

Attention: The internal data of table “75” is corrupted!


  • When used in Increased Safety applications, this cable gland may be used with braided cable where the braid and the outer sheath pass into the enclosure. The braid must then be suitably terminated inside the enclosure.
  • Manufactured in Brass (standard), Nickel Plated Brass, 316 Stainless Steel or Aluminium.
  • Brass NPT entries are nickel plated as standard.

Ordering Information

Format for ordering is as follows: Alternate Clamping Ring (S), add suffi x S to ordering information.

Cable Gland TypeSizeThread(OPTIONAL)Cable Gland TypeSizeThread(OPTIONAL)
501/421CM32S501/421C1¼" NPTS

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