{"id":910,"date":"2026-09-10T04:02:00","date_gmt":"2026-09-10T04:02:00","guid":{"rendered":"https:\/\/nm-coupling.net\/products\/nm128-flexible-coupling\/"},"modified":"2026-09-10T06:14:05","modified_gmt":"2026-09-10T06:14:05","slug":"nm128-flexible-coupling","status":"publish","type":"ep_nm_product","link":"https:\/\/nm-coupling.net\/ms\/products\/nm128-flexible-coupling\/","title":{"rendered":"NM128 Flexible Coupling"},"content":{"rendered":"
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Model specifications<\/span><\/p>\n

NM128 technical data<\/h2>\n<\/div>\n

NM128 doubles the nominal torque of NM112 to 140 N.m and increases maximum bore to 55 mm. It is a practical candidate for machinery where shaft diameter and starting load have moved beyond the lighter NM sizes.<\/p>\n<\/div>\n

Model<\/th>Nominal torque<\/th>Speed limit<\/th>D<\/th>D1<\/th>d max<\/th>L<\/th>S<\/th>Radial<\/th>Angular<\/th><\/tr><\/thead>
NM128<\/a><\/strong><\/td>140 N.m<\/span><\/td>3000 rpm<\/span><\/td>128 mm<\/span><\/td>90 mm<\/span><\/td>55 mm<\/span><\/td>70 mm<\/span><\/td>3.5 +\/- 1.0 mm<\/span><\/td>0.07 mm<\/span><\/td>2.5 deg<\/span><\/td><\/tr><\/tbody><\/table><\/div>

D, D1, d max, L, S and radial values are in millimetres. Angular displacement is shown in degrees. On smaller screens, drag the table horizontally to view all columns.<\/p><\/section>\n

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Shaft interface<\/span><\/p>\n

Fit and machining checks<\/h2>\n

The coupling envelope is 128 mm in diameter with a 70 mm length. Measure the actual space between surrounding structures rather than relying on a previous model number, because a larger hub can solve a bore issue while creating a guard-clearance problem.<\/p>\n<\/div>\n

Operating duty<\/span><\/p>\n

Where this size fits<\/h2>\n

For mixers, conveyors, pumps and similar industrial drives, use the 140 N.m nominal rating as the first screen and describe how the machine starts. A loaded conveyor start and a steady pump at the same running power do not impose the same transient conditions.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

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Alignment and assembly<\/h2>\n

The stated separation for NM128 is 3.5 +\/- 1.0 mm. Keep radial misalignment within 0.07 mm and angular misalignment within 2.5 degrees, then inspect the elastomer after commissioning if the installation previously showed uneven wear.<\/p>\n

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D \/ D1<\/strong>128 \/ 90 mm<\/span><\/div>\n
L \/ S<\/strong>70 mm \/ 3.5 +\/- 1.0 mm<\/span><\/div>\n
Alignment<\/strong>0.07 mm radial \/ 2.5 deg angular<\/span><\/div>\n<\/div>\n<\/div>\n
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Prepare the NM128 RFQ<\/h2>\n

A useful NM128 quotation request combines mechanical interface and duty data: both bores, both keyways, rpm, torque or motor power, driven machine, quantity and any controlled fit. Attach the shaft drawing when shoulders or unusual keys affect machining.<\/p>\n

Use the NM selection guide →<\/a><\/p>\n<\/div>\n<\/div>\n<\/section>\n

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Flexible element<\/span><\/p>\n

Material and service conditions<\/h2>\n<\/div>\n

NBR is standard for the flexible ring. If the drive is near heat, lubricants or process chemicals, identify the exposure and any required material so the elastomer is not chosen by appearance alone.<\/p>\n<\/div>\n

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Element<\/h3>\n

State the required material or service environment; do not identify elastomer chemistry by colour alone.<\/p>\n<\/div>\n

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Machining<\/h3>\n

List the driving and driven bores and keyways separately, including controlled fits where required.<\/p>\n<\/div>\n

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Speed<\/h3>\n

NM128 is rated to 3000 rpm; verify actual running speed before final selection.<\/p>\n<\/div>\n

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Torque<\/h3>\n

The nominal rating is 140 N.m. Describe unusual starts, reversing or shock in the enquiry.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

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Compare the nearest NM sizes<\/h2>\n

When 55 mm bore capacity or 140 N.m torque is insufficient, review NM148. When the application is comfortably below those limits, NM112 may provide a smaller diameter and shorter assembly.<\/p>\n

NM112<\/a>NM148<\/a><\/div>\n<\/div>\n
Compare all NM sizes<\/a><\/div>\n<\/div>\n<\/section>\n
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NM128 quick answers<\/h2>\n
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\nWhat torque and speed define NM128?<\/summary>\n
NM128 is listed at 140 N.m nominal torque with a 3000 rpm rated speed limit.<\/div>\n<\/details>\n
\nHow large can the finished bore be?<\/summary>\n
The stated maximum bore is 55 mm. Bore, keyway and fit still need to be checked together for the ordered hub.<\/div>\n<\/details>\n
\nWhat shaft data should I send?<\/summary>\n
Send the driving and driven shaft diameters, both keyways, running speed, duty, quantity and any drawing-controlled fit.<\/div>\n<\/details>\n<\/div>\n<\/section>","protected":false},"excerpt":{"rendered":"

NM128 provides 140 N.m nominal torque, up to 55 mm bore capacity and a rated speed limit of 3000 rpm. It is suited to mid-range pumps, blowers, mixers and machinery when torque, shaft fit, alignment and installation space are all within the model limits.<\/p>","protected":false},"featured_media":930,"template":"","class_list":["post-910","ep_nm_product","type-ep_nm_product","status-publish","has-post-thumbnail","hentry"],"_links":{"self":[{"href":"https:\/\/nm-coupling.net\/ms\/wp-json\/wp\/v2\/ep_nm_product\/910","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nm-coupling.net\/ms\/wp-json\/wp\/v2\/ep_nm_product"}],"about":[{"href":"https:\/\/nm-coupling.net\/ms\/wp-json\/wp\/v2\/types\/ep_nm_product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nm-coupling.net\/ms\/wp-json\/wp\/v2\/media\/930"}],"wp:attachment":[{"href":"https:\/\/nm-coupling.net\/ms\/wp-json\/wp\/v2\/media?parent=910"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}