Reed Relays and
Electronics India Limited
Manufacturer of Reed Switches, Reed Sensors and Reed-based products
Reed Relays and Electronics India Limited Incorporated in 1971

Actuation Distances for UM-0018-H Reed Switches

For easy selection of AT band and Magnet for an application, we offer Actuation distances for the UM-0018-H Reed Switch in cropped, SMD and Vertical Mount formations. The various combinations of standard AT Bands and magnets are covered, from the lower AT bands to the higher AT bands. Each AT band lists distances when actuated with our standard magnets. Although some of the AT band / magnet combinations of the UM-0018-H Reed Switch will produce similar actuating distances, selecting the right AT band and magnet for an application is important. Our Usage Notes below addresses these topics.

All distances given are in mm and standard tolerances of ±0.5 mm apply.

Actuation Distances for Cropped Leads

cropped reed switch actuation direction
Magnet actuation direction

Operate Band 7-12 (AT)

MagnetDimensionsOperate DistanceRelease Distance
NDR-T4.0 x 1.5 x 1.52.5 – 4.53.0 – 5.0
NDR-S6.0 x 2.5 x 2.57.5 – 9.08.0 – 9.5
NDR-M8.0 x 3.0 x 3.09.0 – 12.010.0 – 12.5
NDR-L19.0 x 4.0 x 4.015.5 – 20.517.0 – 21.0
NDC-TØ2.0 x 4.03.5 – 5.54.0 – 6.0
NDC-SØ3.0 x 7.08.0 – 10.09.0 – 11.0
NDC-MØ4.0 x 10.012.0 – 15.513.0 – 16.0
NDC-LØ8.0 x 15.023.0 – 30.025.0 – 30.5

Operate Band 12-17 (AT)

MagnetDimensionsOperate DistanceRelease Distance
NDR-T4.0 x 1.5 x 1.52.0 – 3.03.0 – 3.5
NDR-S6.0 x 2.5 x 2.55.5 – 7.56.0 – 8.0
NDR-M8.0 x 3.0 x 3.08.0 – 9.09.0 – 10.5
NDR-L19.0 x 4.0 x 4.013.5 – 15.515.0 – 17.0
NDC-TØ2.0 x 4.03.0 – 3.53.5 – 4.0
NDC-SØ3.0 x 7.06.5 – 8.07.0 – 9.0
NDC-MØ4.0 x 10.010.5 – 12.012.0 – 13.0
NDC-LØ8.0 x 15.020.0 – 23.022.0 – 25.0

Actuation Distances for SMD Formed Leads

SMD formed reed switch actuation direction
Magnet actuation direction

Operate Band 7-12 (AT)

MagnetDimensionsOperate DistanceRelease Distance
NDR-T4.0 x 1.5 x 1.53.0 – 5.03.5 – 5.5
NDR-S6.0 x 2.5 x 2.57.5 – 10.58.0 – 11.0
NDR-M8.0 x 3.0 x 3.010.0 – 13.510.5 – 14.0
NDR-L19.0 x 4.0 x 4.017.5 – 23.518.0 – 24.0
NDC-TØ2.0 x 4.03.5 – 6.04.0 – 6.5
NDC-SØ3.0 x 7.08.5 – 11.09.0 – 12.0
NDC-MØ4.0 x 10.013.0 – 17.013.5 – 18.0
NDC-LØ8.0 x 15.026.0 – 34.027.0 – 35.0

Operate Band 12-17 (AT)

MagnetDimensionsOperate DistanceRelease Distance
NDR-T4.0 x 1.5 x 1.52.5 – 2.03.0 – 3.5
NDR-S6.0 x 2.5 x 2.56.0 – 7.57.0 – 8.0
NDR-M8.0 x 3.0 x 3.09.0 – 10.010.0 – 10.5
NDR-L19.0 x 4.0 x 4.015.0 – 17.517.0 – 18.0
NDC-TØ2.0 x 4.03.0 – 3.53.5 – 4.0
NDC-SØ3.0 x 7.07.0 – 8.58.0 – 9.0
NDC-MØ4.0 x 10.011.0 – 13.012.5 – 13.5
NDC-LØ8.0 x 15.022.0 – 26.025.0 – 27.0

Actuation Distances for Horizontal Mounting on PCBs

Goal-post formed Leads and magnet
Magnet actuation direction

Operate Band 7-12 (AT)

MagnetDimensionsOperate DistanceRelease Distance
NDR-T4.0 x 1.5 x 1.5
NDR-S6.0 x 2.5 x 2.5
NDR-M8.0 x 3.0 x 3.0
NDR-L19.0 x 4.0 x 4.0
NDC-TØ2.0 x 4.0
NDC-SØ3.0 x 7.0
NDC-MØ4.0 x 10.0
NDC-LØ8.0 x 15.0

Operate Band 12-17 (AT)

MagnetDimensionsOperate DistanceRelease Distance
NDR-T4.0 x 1.5 x 1.5
NDR-S6.0 x 2.5 x 2.5
NDR-M8.0 x 3.0 x 3.0
NDR-L19.0 x 4.0 x 4.0
NDC-TØ2.0 x 4.0
NDC-SØ3.0 x 7.0
NDC-MØ4.0 x 10.0
NDC-LØ8.0 x 15.0

Actuation Distances for Vertical Mounting on PCBs

Welded Leads and magnet
Magnet actuation direction

Operate Band 7-12 (AT)

MagnetDimensionsOperate DistanceRelease Distance
NDR-T4.0 x 1.5 x 1.53.0 – 4.54.0 – 5.0
NDR-S6.0 x 2.5 x 2.58.0 – 10.59.5 – 11.5
NDR-M8.0 x 3.0 x 3.011.0 – 14.012.5 – 15.0
NDR-L19.0 x 4.0 x 4.020.0 – 25.023.0 – 25.5
NDC-TØ2.0 x 4.04.0 – 5.55.0 – 6.5
NDC-SØ3.0 x 7.09.0 – 11.010.0 – 12.0
NDC-MØ4.0 x 10.015.0 – 18.016.5 – 18.5
NDC-LØ8.0 x 15.029.0 – 35.031.5 – 36.0

Operate Band 12-17 (AT)

MagnetDimensionsOperate DistanceRelease Distance
NDR-T4.0 x 1.5 x 1.52.5 – 3.53.0 – 4.5
NDR-S6.0 x 2.5 x 2.57.0 – 8.09.0 – 9.5
NDR-M8.0 x 3.0 x 3.09.5 – 11.510.5 – 13.0
NDR-L19.0 x 4.0 x 4.017.0 – 20.019.0 – 23.0
NDC-TØ2.0 x 4.03.0 – 4.03.5 – 5.5
NDC-SØ3.0 x 7.08.0 – 9.09.0 – 10.5
NDC-MØ4.0 x 10.012.5 – 15.014.5 – 16.5
NDC-LØ8.0 x 15.025.0 – 29.027.5 – 31.5

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