NYLON INSERT LOCK NUTS.

A nylon insert lock nut is a nut with a non-metallic locking ring that adds prevailing resistance when engaged by a mating bolt or rod thread. This helps distinguish it from a plain hex nut. Selecting a part requires both the mating-thread specification and the service conditions. For an LD Screw quotation, include the nut profile, metal material and grade, finish, insert requirements and the agreed performance criteria.

Selection checklist for nylon insert lock nuts

Use the fields below when comparing a drawing, sample or purchasing list. The metric and inch thread examples show notation only; they are not a list of available sizes.

Selection item	Information to send	Why it matters
Mating thread	Full designation, such as M10 × 1.5 or 3/8-16 UNC, plus tolerance or thread class.	The diameter, pitch or thread count and system must match.
Profile and clearance	Nut standard and edition, height, width across flats and any assembly-space limits.	A locking insert and nut profile need room in the actual joint.
Metal material and grade	Specified steel or stainless designation and the applicable nut grade or property class.	The metal body has mechanical requirements separate from the locking feature.
Finish and mating component	Coating specification, lubrication requirements and bolt or rod condition.	These are part of the agreed assembly and test conditions.
Service environment	Operating temperature, chemicals, exposure and installation conditions.	The insert must suit the actual service conditions.
Performance and reuse	Required prevailing-torque criteria, test standard and any permitted reuse conditions.	Locking performance needs a defined acceptance basis.
Order and documentation	Quantity, packing, destination, requested samples and inspection records.	These details support the quotation and order review.

What to include in a lock-nut RFQ

Thread and fit: Provide the nominal diameter, thread pitch and the mating bolt or rod specification. Confirm whether the application requires a particular nut profile, height or across-flats dimension.

Material and finish: State the metal grade or property class and the required coating. The insert material, colour and finish visible in the photo are examples; your order specification determines the supplied part.

Quantity and documentation: Include order quantity, packing format, destination and any inspection or document requirements. If the nut must conform to a named standard, put that standard and edition on the drawing or RFQ.

Check the application before ordering

The nylon ring and the mating thread need to suit the expected temperature, chemicals, installation method and service environment. A lock nut does not replace a joint-design check. If the fastener will be reused or the locking performance is safety-critical, ask your engineer to specify the required prevailing-torque and reuse criteria.

Nylon insert or flange lock nut?

A nylon insert lock nut uses an insert to add resistance to rotation. A flange nut has an integral bearing surface; a flange lock nut may use a different locking feature. Send a drawing or sample when the mating surface or locking method matters. For a flange form, see our hex flange nuts page.

RFQ checklist

Send us: thread size and pitch; mating bolt details; required standard or drawing; metal material and grade; finish; insert and performance requirements; quantity; packing; and destination. We will confirm the achievable specification and delivery terms in the quotation.

Performance standards to identify in the RFQ

ISO 2320 addresses functional testing of prevailing-torque steel nuts, including applicable non-metallic insert types. For inch-series requirements, ASME B18.16.6 covers prevailing-torque locknuts. These publisher summaries help identify the subject of each standard; the order must state the required standard, edition and acceptance criteria. Linking a standard does not establish product compliance.

Common nylon insert lock nut questions

How does the nylon insert differ from a plain hex nut?

The insert engages the mating thread and creates additional resistance to rotation. A plain hex nut has no such insert. The chosen locking method still needs to suit the designed joint and its service conditions.

Does a blue insert identify the material grade or temperature limit?

No. Insert colour alone is not a specification for the metal body, insert material, mechanical grade or operating limit. Include the required designations and service temperature, then confirm them against the product specification agreed for the order.

Can I select one for heat or chemical exposure?

Send the actual temperature range, chemicals and exposure conditions before selecting the insert. Suitability depends on the specified material and assembly. Do not infer an operating limit from a photograph or from a different lock-nut type.

Is prevailing torque the same as installation torque?

No. Prevailing torque describes the resistance associated with the locking feature. It is not, by itself, the tightening instruction needed to obtain the required joint clamp force. Use the approved installation and test procedure for the actual fastener combination; no universal torque value is specified by this product page.

Can a nylon insert lock nut be reused?

Confirm the applicable assembly procedure and acceptance criteria. Removal and reinstallation can affect locking behaviour, so there is no universal reuse count for every part and application. If reuse is required, specify the performance to be demonstrated after the agreed installation and removal cycles.

What should a US buyer send for a matching bolt or rod order?

State whether the assembly uses metric or inch threads, with diameter, pitch or threads per inch, thread series and fit. Include the nut profile, mating rod or bolt specification, grades, finish, service conditions, performance requirements and quantities. A rough diameter conversion does not establish compatibility.

Request an order-specific quotation

Send your drawing or sample reference, complete nut and mating-thread specification, service conditions, locking-performance criteria, quantity, packing, destination and required documents. See our workshop and the materials and grades guide, then send your lock-nut RFQ to LD Screw. Any supply, sample and documentation requirements are confirmed in the quotation.