{"id":876,"date":"2026-09-10T03:59:42","date_gmt":"2026-09-10T03:59:42","guid":{"rendered":"https:\/\/nm-coupling.net\/technical-guides\/selection-guide\/"},"modified":"2026-09-10T06:13:59","modified_gmt":"2026-09-10T06:13:59","slug":"selection-guide","status":"publish","type":"page","link":"https:\/\/nm-coupling.net\/pl\/technical-guides\/selection-guide\/","title":{"rendered":"NM Coupling Selection Guide"},"content":{"rendered":"

NM selection is easiest when you separate what the table can answer from what the quotation must answer. The table can screen nominal torque, speed, bore and envelope. It cannot tell you a universal peak-torque allowance, final hub material, finished keyway or elastomer hardness for every project.<\/p>\n

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Establish the duty<\/h3>\n

Use design torque where available. If you only have motor power and rpm, include both and describe starts, reversing and shock.<\/p>\n<\/div>\n

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Screen torque & speed<\/h3>\n

Find NM models whose nominal torque and speed limit cover the operating point.<\/p>\n<\/div>\n

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Check the shafts<\/h3>\n

Both required bores must stay within d max. Then compare D, D1, L and S with the installation envelope.<\/p>\n<\/div>\n

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Confirm the order scope<\/h3>\n

Add keyways, quantity, elastomer request, hub material request and destination for quotation.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

Do not mix nominal torque with a guessed overload factor.<\/h2>\n

The standard NM range uses nominal torque. Some other NM references on the market publish different ratings, but those values are not interchangeable with this range. If your application has pronounced starts or shock, send the duty for review rather than applying an unconfirmed overload factor.<\/p>\n

Bore capacity can change the size after torque is already satisfied.<\/h2>\n

A small model may carry the operating torque but still be unusable because one shaft exceeds its specified maximum bore. Move upward only after checking that the larger model also fits the available outside diameter and axial space. For NM194 and NM214, remember that the rated speed limit drops to 1500 rpm.<\/p>\n

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Range table<\/span><\/p>\n

Use one table for the first screen.<\/h2>\n<\/div>\n

On mobile, drag horizontally to keep all columns visible rather than losing dimensional context.<\/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>
NM50<\/a><\/strong><\/td>5 N.m<\/span><\/td>3000 rpm<\/span><\/td>50 mm<\/span><\/td>33 mm<\/span><\/td>19 mm<\/span><\/td>25 mm<\/span><\/td>2 +\/- 0.5 mm<\/span><\/td>0.03 mm<\/span><\/td>3.0 deg<\/span><\/td><\/tr>
NM67<\/a><\/strong><\/td>13 N.m<\/span><\/td>3000 rpm<\/span><\/td>67 mm<\/span><\/td>46 mm<\/span><\/td>28 mm<\/span><\/td>30 mm<\/span><\/td>2.5 +\/- 0.5 mm<\/span><\/td>0.03 mm<\/span><\/td>3.0 deg<\/span><\/td><\/tr>
NM82<\/a><\/strong><\/td>28 N.m<\/span><\/td>3000 rpm<\/span><\/td>82 mm<\/span><\/td>53 mm<\/span><\/td>32 mm<\/span><\/td>40 mm<\/span><\/td>3.0 +\/- 1.0 mm<\/span><\/td>0.05 mm<\/span><\/td>3.0 deg<\/span><\/td><\/tr>
NM97<\/a><\/strong><\/td>45 N.m<\/span><\/td>3000 rpm<\/span><\/td>97 mm<\/span><\/td>69 mm<\/span><\/td>42 mm<\/span><\/td>50 mm<\/span><\/td>3.0 +\/- 1.0 mm<\/span><\/td>0.05 mm<\/span><\/td>2.5 deg<\/span><\/td><\/tr>
NM112<\/a><\/strong><\/td>70 N.m<\/span><\/td>3000 rpm<\/span><\/td>112 mm<\/span><\/td>79 mm<\/span><\/td>48 mm<\/span><\/td>60 mm<\/span><\/td>3.5 +\/- 1.0 mm<\/span><\/td>0.07 mm<\/span><\/td>2.5 deg<\/span><\/td><\/tr>
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>
NM148<\/a><\/strong><\/td>280 N.m<\/span><\/td>3000 rpm<\/span><\/td>148 mm<\/span><\/td>107 mm<\/span><\/td>65 mm<\/span><\/td>80 mm<\/span><\/td>3.5 +\/- 1.0 mm<\/span><\/td>0.07 mm<\/span><\/td>2.0 deg<\/span><\/td><\/tr>
NM168<\/a><\/strong><\/td>500 N.m<\/span><\/td>3000 rpm<\/span><\/td>168 mm<\/span><\/td>124 mm<\/span><\/td>75 mm<\/span><\/td>90 mm<\/span><\/td>3.5 +\/- 1.5 mm<\/span><\/td>0.10 mm<\/span><\/td>2.0 deg<\/span><\/td><\/tr>
NM194<\/a><\/strong><\/td>840 N.m<\/span><\/td>1500 rpm<\/span><\/td>194 mm<\/span><\/td>140 mm<\/span><\/td>85 mm<\/span><\/td>100 mm<\/span><\/td>3.5 +\/- 1.5 mm<\/span><\/td>0.10 mm<\/span><\/td>2.0 deg<\/span><\/td><\/tr>
NM214<\/a><\/strong><\/td>1000 N.m<\/span><\/td>1500 rpm<\/span><\/td>214 mm<\/span><\/td>157 mm<\/span><\/td>95 mm<\/span><\/td>110 mm<\/span><\/td>4.0 +\/- 2.0 mm<\/span><\/td>0.10 mm<\/span><\/td>2.0 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

What to put in the RFQ<\/h2>\n

State the NM model if selected, running speed, design torque or motor power, driving and driven shaft diameters, both keyways, quantity and destination. Add starts per hour, reversing, shock, environment and any material request when they matter. If the application is a replacement, include the old model and measured dimensions, but treat those as identification aids rather than substitutes for shaft data.<\/p>\n

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Want a second pair of eyes on the size?<\/h2>\n

Send the duty and shafts. We will check the model screen before the bore\/keyway scope is frozen.<\/p>\n<\/div>\n

Review My Selection<\/a><\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"

Select NM50-NM214 by nominal torque, speed and bore first, then confirm duty, keyways, envelope and elastomer requirements.<\/p>","protected":false},"author":1,"featured_media":0,"parent":860,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-876","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/nm-coupling.net\/pl\/wp-json\/wp\/v2\/pages\/876","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nm-coupling.net\/pl\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/nm-coupling.net\/pl\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/nm-coupling.net\/pl\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/nm-coupling.net\/pl\/wp-json\/wp\/v2\/comments?post=876"}],"version-history":[{"count":2,"href":"https:\/\/nm-coupling.net\/pl\/wp-json\/wp\/v2\/pages\/876\/revisions"}],"predecessor-version":[{"id":953,"href":"https:\/\/nm-coupling.net\/pl\/wp-json\/wp\/v2\/pages\/876\/revisions\/953"}],"up":[{"embeddable":true,"href":"https:\/\/nm-coupling.net\/pl\/wp-json\/wp\/v2\/pages\/860"}],"wp:attachment":[{"href":"https:\/\/nm-coupling.net\/pl\/wp-json\/wp\/v2\/media?parent=876"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}