BRASS NUTS, COLD FORGED BRASS NUTS
A brass cold forged nut is an internally threaded fastener made by cold forming a near-net blank, then producing the internal thread and inspecting the finished mating dimensions. Cable Glands India offers drawing-based review for electrical OEMs, EPC contractors, utilities and distributors procuring brass nuts for electrical enclosures, terminal assemblies and industrial hardware. The choice of blank geometry, thread fit, bearing face and material condition governs whether the nut seats and develops the intended clamp load.
Price: US$ 16/kg
Detailed product overview
Hex nuts
Across flats, height and bearing diameter define the basic installation envelope. Confirm socket clearance with the enclosure installed. Where a washer is present, model the washer ID and the chamfer on the nut together. A bore chamfer eases starting but consumes useful thread engagement. Check the first complete thread on the entry face and the last complete thread on the exit side. Deep sockets can foul insulating barriers even if the wrench fits the bare nut. A drawing with a seating face datum makes bearing face runout measurable.
Square nuts
Square blanks are often retained in channels or molded pockets that prevent rotation. Corner radius and across-corner dimensions matter as much as across flats. A burr at the pierce exit can stop a nut from sliding into a closely fitted pocket. Specify how the assembly operator or feeder establishes the correct face orientation. Confirm pocket width, clearance, assembly access and required pull-out or torque-out verification.
Thin and jam nuts
A reduced-height nut fits limited thread projection and can be paired with a second nut in a joint designed for that arrangement. Effective engagement depends on usable complete threads after chamfers. Define the tightening sequence and mating component on the assembly drawing. Carry the intended clamp load and service temperature into the verification plan. Heavy and tall nuts provide a different engagement envelope and have different socket clearance and mass implications.
Flange nuts
An integral flange spreads the load over a defined bearing diameter. Check the support underneath its full footprint, particularly near slots or edges. An as-formed fillet at the body-to-flange transition can influence socket engagement. Serrated bearing faces require a stated pattern and mating surface. Smooth faces are easier to characterize where the joint relies on a controlled washer or plated contact surface. Check marks on the mating part after tightening.
Cap and acorn nuts
A closed end covers the projecting mating thread. Specify usable blind thread depth and the maximum protrusion past the joint stack. If the bolt bottoms inside the cap, torque can rise before the nut clamps the joint. High crown and low crown styles differ in overall clearance and internal depth. Use a section view to define crown wall, starting chamfer, bore depth and thread termination.
Locking, slotted and special nuts
Distinguish a plain formed nut from a prevailing-torque nut, a slotted or castellated nut, or a captive nut geometry. Each locking feature requires its own validation and may involve machining, staking or an insert. Test prevailing torque, installation torque and reuse as defined by the design. Any slot must be coordinated with the mating pin position. Thin-wall bodies and deep slots require a dedicated feasibility review.
Key features
- Cold formed and pierced blank, with blind forms evaluated separately.
- Metric or Unified series as specified; tap route and fit agreed with drawing.
- Across flats, thickness, flange OD, face condition and axial alignment as applicable.
- Finished thread gauge, dimensional report and agreed proof load or torque test.
- Drawing-based material, finish and dimensional review before tooling.
Related engineering terms and design details
Internal thread class
State nominal diameter, pitch, tolerance class and mating thread. Identify acceptance after coating. A GO gauge checks functional thread fit within its intended gauging rules. The complementary NOT GO gauge and length checks address different characteristics. Specify how gauging is done near blind bottoms and how fully formed engagement is counted.
Pierced bore and tap allowance
Bore diameter, straightness and residual wall affect tapping stability. Cutting taps and form taps require different starting holes. Where the nut is blind, allow tool clearance and a place for displaced material or chips. Keep entrance chamfer separate from the load-bearing thread. Section first-off samples when the finished thread or bore shape cannot be judged from the ends.
Bearing-face flatness
A bearing face that tilts relative to the thread axis can contact on one edge. Define a datum and inspection setup that reflects the assembly. Check the face after any restrike and coating. Review whether the washer conforms or rocks under the intended preload. On electrical assemblies distinguish mechanical seating from any specified contact resistance test.
Proof-load and torque verification
When a minimum proof load is required, put the numeric value and fixture method in the purchase specification. Define test mandrel, engagement length, acceptance and disposition after test. Standard steel property classes cannot be inferred for brass. For torque-driven assembly validate the fastener, mating stud, washer, lubrication and finish together with the actual tool.
Nickel and tin plated brass nuts
Call out coating type, thickness and measurement surfaces. Where threads are plated, agree the functional gauge condition after processing. Thread friction, tool response and continuity through the joint can change with the selected finish. Use assembly samples to confirm clamp and contact behavior where electrical performance is important.
Square-pocket antirotation
Use the pocket and the nut together when specifying torque-out and location. A shallow pocket can allow the corners to climb under tightening. Provide corner relief if the pocket process leaves a radius incompatible with the nut. Record which face contacts the pocket floor so inspection uses the correct orientation.
Technical specifications
| Characteristic | Specification basis |
|---|---|
| Nut body | Cold formed and pierced blank, with blind forms evaluated separately. |
| Internal thread | UNC, UNS, UNF, BSW and ISO metric (coarse or fine), as specified on the drawing. Confirm pitch or threads per inch, fit and gauging requirements. |
| Bearing controls | Across flats, thickness, flange OD, face condition and axial alignment as applicable. |
| Release checks | Finished thread gauge, dimensional report and agreed proof load or torque test. |
| Size range | Nominal thread diameter: 1/8″–2″ (inch range) or 3–50 mm (metric range), depending on design. |
| Dimensional tolerances | Drawing-controlled. Identify finished dimensions and functional datums. |
| Finish | Bare or a drawing-specified coating, subject to application and process review. |
| Ordering units | Price listed in USD per kilogram. Provide delivery quantity by mass or piece count and agree the unit on the quotation. |
Brass grades and international equivalents
| UNS reference | EN or common designation | Alloy family | Procurement note |
|---|---|---|---|
| UNS C26000 | CuZn30 / CW505L | Cartridge brass | Candidate for demanding forming, especially where substantial upset or tail deformation is expected. Verify the feedstock temper and formability with the producing mill. |
| UNS C26800 | CuZn33 / CW506L (comparison) | Yellow brass | Candidate where the selected wire or rod grade and temper fit the geometry. Check both specifications before allowing substitution. |
| UNS C27000 | CuZn36 / CW507L (comparison) | Yellow brass | Compare against the approved chemistry, incoming form and test requirements before any substitution. Qualify fit, finish and forming behavior with samples. |
| UNS C36000 | Free-cutting brass | Machining comparison | Use for route comparison when machining dominates. Evaluate an alternate grade or process if the cold deformation required by the drawing is substantial. |
| UNS C69300 | CuZn21Si3P / CW724R | Silicon brass | Lead-free specification candidate subject to approved chemistry and application requirements. Evaluate the actual forming route and feedstock before committing to a cold forged design. |
Use these designations as cross-reference guidance. National standards may specify different compositional limits, allowable product forms, delivery conditions and mechanical properties. The approved material specification and lot documentation govern acceptance. Review the alloy and temper for the cold work required by the drawing.
Product types and variants
| Family | Typical scope | Design review |
|---|---|---|
| General through nuts | Hex, square and other compatible open profiles | Check across flats, axial height and thread entrance against wrench and assembly space. |
| Reduced-height nuts | Thin and jam styles | Confirm usable thread engagement, mating bolt projection and the tightening sequence. |
| Extended body | Tall and heavy hex styles | Check total height, wrench engagement and minimum usable threads. |
| Bearing flange | Smooth or drawing-specific serrations | Define bearing footprint and test the selected mating material. |
| Closed end | Cap and acorn profiles | Check crown envelope, blind thread depth and bottoming clearance. |
| Locking and capture | Slotted, castellated, captive or prevailing-torque designs | Review the added feature, secondary operations and functional acceptance. |
Industrial applications
| Application | Typical procurement requirement |
|---|---|
| Electrical panels | Busbar supports and terminal hardware where captive location and bearing support are defined. |
| Utility equipment | Cabinet hardware and non-structural accessories where the approved assembly drawing calls for brass. |
| Distribution | Drawing and revision controlled stock for matching bolts, washers and panel hardware. |
Manufacturing process
How to specify the part on a drawing
Start with an installed assembly view and a separate detail of the loose fastener. The assembly view identifies mating components, access for tools, neighboring parts and the required service position. The detail establishes dimensions that can be measured on incoming material. Use a section view when an internal surface, depth or transition controls fit. Give each critical dimension a datum and state whether the limit applies before or after finishing. The same dimension should have a single controlling callout. A purchase order should identify the released drawing revision and any governing specification so two suppliers can interpret the part consistently.
Feasibility of the cold forming route
The sequence starts by deciding how much metal needs to move at each die station. The finished shape is considered together with the feedstock diameter, material condition, lubricant, tool access and method of ejecting the blank. A large change in section may need multiple forming operations. Metal must be able to flow into the head or flange without producing folds at the transition. Sharp corners, narrow webs and asymmetric masses can require radius changes or a secondary operation. Where a radius is part of the application, the drawing should show which mating geometry provides clearance so it can be reviewed before tools are made.
Incoming material and lot identity
Define the alloy by designation and a material specification suitable for the incoming wire or rod. Temper, dimensions and surface condition can be as important to heading as chemical composition. Receive material with the lot identity and documentation agreed in the order. Where chemistry verification is required, specify the method and limits on the inspection plan. Verify lead and other restricted substances against the applicable customer requirement and the actual grade. Keep the incoming lot connected to the production and finishing batches so a process change or returned part can be traced. An equivalence table helps with purchasing discussions but the approved drawing and certificate govern acceptance.
Cutoff, blank development and forming
A cutoff establishes the volume available to fill the finished geometry. Consistent cutoff mass, straight feed and a sound end condition support repeatable formation. The first station can prepare a blank for a controlled upset. Later stations develop the profile, size an important diameter or create an internal recess where applicable. The tooling sequence and checks depend on the product. Trial blanks should be inspected at intermediate operations so a defect can be traced to the stage that created it. Record the approved first pieces before production and recheck the relevant characteristics after tool adjustment or replacement.
Secondary operations and cleaning
Secondary machining can establish a dimension that requires a tighter tolerance, a controlled finish or a feature that is difficult to form with an axial tool. Call out whether each functional feature may be machined or must remain as formed. Burrs at holes, grooves and transitions can interfere with plating or assembly. State the allowed edge condition rather than assuming a general deburr note gives the desired result. Use a cleaning process compatible with the finish and the end application. Check hidden recesses when they can retain lubricant, chips or debris. A finished part should be measured after the operations that can affect its fit.
Coating specification and inspection
A finish callout should identify the coating, significant surfaces, required thickness, any undercoat and the method used to verify it. The agreed acceptance condition should also address color or cosmetic appearance when the part remains visible. Internal features, recessed faces and narrow pockets can be difficult to measure. Select reference surfaces or an appropriate test section before the order is released. Specify the dimensions that must be checked after finishing and the relevant gauge condition. Use finished parts for assembly tests because friction, clearance and electrical behavior can differ from the bare part. If a coating requires masking, show the boundary on the drawing.
Quality standards, certifications and inspection
| Requirement | What to specify |
|---|---|
| Quality management | ISO 9001:2015 quality management system. Where a certificate is required, request its current edition, applicable scope and manufacturing site. |
| Dimensional references | ISO 4032, ISO 4035 and ASME B18.2.2 may be useful as dimensional references for the applicable nut profiles. Specify the edition, size and intended scope, then confirm any departures on the drawing. Agree separately on material, thread fit, mechanical properties and bearing face requirements. A tall nut intended to increase engagement still depends on complete threads and enough mating stud length. For a blind cap nut, a length stack is usually a more useful approval input than overall crown height alone. When a nut is trapped inside molded hardware, provide the pocket and assembly procedure alongside the component drawing. |
| Thread specification | Specify ISO metric or Unified thread form and fit where applicable, using the agreed thread standard and gauge condition. |
| Material report | Request traceable alloy and temper documentation. Specify the incoming product form and the required report format at enquiry. |
| Regulatory declarations | Provide the applicable RoHS or REACH documentation requirements and any restricted-substance criteria. The declaration depends on the part, grade and application. |
| Approval records | Agree first article measurements, functional test reports, control plan or PPAP submission requirements before production. |
First article approval
Set the first article scope before tooling starts. A report can map measured values to numbered drawing callouts and identify the actual alloy, finish and sample lot. Use an inspection fixture that matches the drawing datums. Separate variable measurements, such as a measured height, from attribute checks, such as acceptance by a functional gauge. Confirm who approves the first article and which changes trigger resubmission. Where the result depends on a mating part, supply representative hardware or a controlled test fixture. Samples used for functional approval should identify their process route so prototype results are interpreted in context.
Production control and sampling
A control plan can identify where each characteristic is checked, how it is measured and what action follows a failed sample. High-risk characteristics may call for different checks from general dimensional features. If the purchase requires a particular sampling procedure, specify the inspection level and acceptance criteria alongside the test frequency. For automatic sorting, define the detectable defects and set up representative limit samples where appropriate. After a stoppage or tool change, identify the first-off verification needed before continuing. Keep the inspection lot linked to the accepted shipment and isolate suspect material while measurements are reviewed.
Measurement and calibration
Choose a measurement method that can resolve the drawing tolerance and reach the actual feature. Use an optical system, fixture, thread gauge or dimensional instrument according to the inspection plan. A measurement at the edge of a radius can vary with fixturing even when the part is stable, so define the measurement location. If the buyer will perform a different incoming method, compare results on the same samples before routine supply. Identify gauge size, tolerance class and condition where relevant. For disputed results, retain samples with lot records and use an agreed reference method.
Assembly validation and use limits
An assembly can fail through the receiving component, coating, fit or installation method even when every loose fastener dimension passes. Use the production-intent mating materials and the intended tools for validation. Define maximum and minimum assembly conditions where variation affects the outcome. Record the loading direction, tightening or setting sequence, and how failure is judged. For electrical equipment, distinguish a dimensional check from qualification of the equipment or verification of continuity through a finished joint. Where vibration, heat, moisture or chemicals affect performance, identify the applicable tests and acceptance criteria with the equipment designer.
Packing and incoming inspection
The packaging method should protect formed heads, edges and coating and should preserve the identity of each lot. Identify part number, revision, quantity, finish and lot information on the package where required. A buyer feeding components automatically may need an agreed cleanliness level or packing arrangement. Small mixed variations can look alike, so separate revisions, sizes and finishes in order lines and containers. Retain enough samples to compare a delivered lot with its approval data if a fit issue arises. Define the receiving inspection that will be used for subsequent deliveries and record any deviations through a controlled approval.
Engineering changes and repeat supply
When a drawing or finish changes, review the effect on dies, gauges, fixtures, sample approval and inventory. Changes in mating hardware can also affect fit even when the fastener drawing stays the same. Identify which revision a given order must receive and whether the new part is interchangeable with current stock. Avoid mixing revisions in the same container unless the customer has agreed to it. On repeat orders send the released documents and reference the approved sample or inspection plan. Flag any change in annual demand, application, packaging or test method when requesting updated pricing.
Why choose Cable Glands India
Cable Glands India reviews drawing-defined fasteners in Jamnagar, Gujarat, India. Request production samples and an agreed inspection plan. Enquiries are welcome from India, the United States, the United Kingdom and other export markets.
Establish the purchase baseline
Include a part number, drawing revision, exact alloy and finish code, annual requirement and anticipated release quantity in the RFQ. Flag a mandatory manufacturing route, such as an as-formed bearing seat, when it is a design requirement. State the units for dimensions and distinguish shop tolerances from functional limits. If the part replaces hardware in an installed assembly, attach the approved earlier drawing or confirm which interfaces must match it. A quantity estimate is useful for tooling review, and lot size helps determine a sensible inspection and delivery plan. Keep samples identified by revision when multiple alternatives are submitted.
Separate dimensional and functional approval
Use dimensional inspection to confirm the component detail. Use an approved assembly fixture or representative mating parts to verify the performance expected in service. Put the numeric criterion, test method and acceptance condition on the purchase documents. Test reports should identify whether samples are bare or finished and whether fixtures reproduce the receiving part. If production tooling is required to reproduce a feature or material condition, qualify parts from the actual tool sequence. Confirm whether any tested or sectioned specimens are retained for records or excluded from the delivery quantity.
Confirm supply scope with the quote
The listed rate gives purchasing teams a common reference in USD per kilogram. A formal quotation identifies the drawing, alloy, finish, inspection scope, volume and any tooling or sample charges. State the destination and packing requirement to align the quote with the delivery program. If parts are supplied in piece counts, agree on the pricing and shipment units to avoid conversion differences. Identify any documentation that must travel with each lot. Cable Glands India can review the part and related fasteners as one enquiry while keeping each drawing revision and acceptance requirement separate.
Frequently asked questions
Can all nut profiles be made from one blank?
The blank and punch sequence depend on envelope, bore and features. Review tall, blind and thin-flanged designs individually.
When should a thin nut be selected?
Use it where the joint is designed for limited engagement or a paired locking arrangement. Verify the assembly load and tightening sequence.
What determines fit after plating?
The thread tolerance, coating distribution and mating thread determine fit. Agree the final gauge condition in advance.
How do I avoid bottoming in an acorn nut?
Compare maximum bolt projection to minimum usable blind depth over the full joint tolerance stack.
Can you quote metric and inch thread forms?
Provide the exact thread series, diameter, pitch or TPI, class and applicable drawing revision.
What makes a nut suitable for a captive pocket?
The nut profile, pocket clearance, corner radius, orientation and antirotation requirement must be compatible.
Can a serrated flange be used for grounding?
Any grounding use requires approval of the complete joint. Define contact surfaces, coating and verification in the assembly specification.
How is proof load specified?
Supply the required load, standard or test procedure, mandrel and acceptance criteria for the brass configuration.
What is the listed rate?
The published rate is US$ 16/kg. Submit the drawing, annual quantity and finish for a formal quotation.
Equivalent product and related terms
| Language | Trade terms |
|---|---|
| Spanish | Tuercas de latón forjadas en frío, tuercas hexagonales, tuercas ciegas |
| Russian | Латунные гайки холодной высадки, шестигранные гайки, колпачковые гайки |
| French | Écrous en laiton forgés à froid, écrous hexagonaux, écrous borgnes |
| Portuguese | Porcas de latão forjadas a frio, porcas sextavadas, porcas cegas |
| Italian | Dadi in ottone stampati a freddo, dadi esagonali, dadi ciechi |
Related brass fasteners and parts
- Brass Cold Forged Parts and Cold Forged Components
- Brass Cold Forged Screws
- Brass Cold Forged Rivets
- Brass Cold Forged Bolts
- Special Brass Cold Forged Fasteners
- Brass Fasteners
Request a quotation
Send your drawing, alloy, finish, order volume and delivery destination. Include mating parts, inspection requirements and approval schedule.