NM Couplings for the United States, Canada & Mexico

Shared catalogue boundary: all countries use the same approved NM50–NM214 ratings. Local pages do not alter torque, speed, dimensions or misalignment values.

United States

State whether shaft dimensions are metric or inch and do not round conversions into a finished bore. OSHA 29 CFR 1910.219 addresses shaft couplings and hazards from fasteners and rotating surfaces. The coupling quotation should therefore be accompanied by envelope dimensions and interface details, while the machine builder remains responsible for a compliant guard and safe installation.

Canada

Confirm province, end-use sector, language requirements and metric/inch drawing format. The Canadian Centre for Occupational Health and Safety describes fixed, interlocked and other safeguards for moving machinery. Use that context to plan the machine-level risk control; no standalone coupling statement should be treated as approval of the assembled machine.

Mexico

Use bilingual English/Spanish drawing notes when requested and keep bore, keyway, torque and speed data numerically identical across documents. NOM-004-STPS-1999 provides machinery protective-system context. The importer and machine integrator should confirm the current rules and documentation that apply to the complete equipment and workplace.

Metric and inch interface control

The NM catalogue is metric, while the United States and parts of Canadian or Mexican supply chains may use inch shaft drawings. Never convert a nominal inch shaft into a rounded metric bore without an approved tolerance decision. Show the original shaft unit, the requested finished bore unit and the acceptance method. A 1-inch shaft is not the same instruction as a 25 mm bore. The key, keyway and fit also need a named standard or complete dimensions.

Commercial documents should use one consistent description: NM model, driving bore, driven bore and quantity. For cross-border programs, add country of destination, importer requirements, packaging, origin marking instructions and requested documentation. Spanish or French translations should preserve model codes, values and units. If a customer requests a certificate or specific material record, include it in the quotation rather than assuming it accompanies every component.

Machine integration and guarding

OSHA's US rule addresses hazards from coupling bolts, nuts, set screws and revolving surfaces. CCOHS describes fixed and interlocked safeguards in Canada, while Mexico's NOM-004-STPS-1999 provides protective-system context. These frameworks differ in legal scope, but they reinforce a practical procurement need: the integrator needs coupling outside diameter, fastener geometry, access and residual interface information to design the complete machine. A component sales page cannot declare the customer's guard compliant.

Operating duty and service support

North American applications may range from indoor packaging machinery to outdoor conveyors, pumps and agricultural equipment. Provide starts per hour, reversals, VFD maximum speed, jam torque and credible peak load. State altitude, temperature, oil, washdown, dust and sunlight. Keep one spare element or assembly strategy based on consequence of downtime, not an invented universal replacement interval. After installation, record alignment, centre gap and hub retention so later troubleshooting has a baseline.

Practical inquiry example

A useful inquiry could specify a 7.5 hp, 1,750 rpm motor driving a process pump, across-the-line start, 1.125-inch driver shaft, 30 mm driven shaft, six starts per day, indoor 35 °C maximum, light oil mist and ten units delivered to Texas, Ontario or Nuevo León. Include both shaft drawings and state whether the finished bores are to remain in their native units. The supplier can then calculate running torque, review start duty, compare the two bores with d max and return a controlled approval drawing. A mixed-unit order without tolerances creates avoidable fit risk.

Approval points for North American orders

• Native units for each shaft, plus explicit finished-bore tolerances
• ANSI, ISO or customer key details named on the drawing
• US English, Canadian French or Mexican Spanish documents as agreed
• Guard envelope and any projecting retention features
• Importer, ship-to location, packing and origin-marking instructions

For a distributor stock program, avoid a vague “universal bore” description. Store the model, two finished bores, keyways and centre-gap reference as a controlled SKU. Separate unbored or pilot-bored inventory from finished parts, and do not present d max as the stock bore.

For a field replacement, ask the technician for a scale photograph and measured shaft data. An old coupling can be worn, modified or incorrectly marked. Comparing the installed dimensions with the catalogue and approved drawing is safer than ordering from color or outside diameter alone.

What to put in an international RFQ

Provide model if known, driver power and speed, continuous and peak torque, both shaft drawings, keyway standard, alignment, temperature, chemical or outdoor exposure, quantity, destination, desired Incoterm, documentation language and any inspection requirement. State whether the finished machine or only a replacement component is being procured.

Regulatory boundary

Official source context: current government or standards information for this region. This site does not provide a legal opinion or declare conformity of the customer's assembled machine.