LNJ Nylon-Tip Set Screws

LNJ combines stainless external threads, an internal hex drive and a soft polymer contact tip. The supplier describes the metal as 304 stainless and promotes gentler contact with optical components, without a material certificate or rated contact force. A complete 15-model dimension table and dedicated photographs cover M2, M3 and M4 sizes. The drawing separates the threaded metal-body length L1 from the protruding polymer tip L2, and lists tip diameter B and an L3 hex-drive value. Individual photographs label overall visible length as L1+L2; for example, LNJ2*3 is pictured at about 3.8 mm overall rather than just 3 mm. Most tips appear green, while the LNJ4*10 photograph has a pale tip, so color is not promised. Pitch, tolerances, polymer grade, installation torque and package count remain unspecified. English artwork identifies the family only.

Fifteen models and two length measures

The table lists LNJ2*3/4, LNJ3*3/4/5/6/8/10/12 and LNJ4*4/5/6/8/10/12. L1 is the metal threaded length; tip projection L2 is 0.8 mm for M2, 1 mm for M3 and 1.5 mm for M4. Dedicated image labels agree with L1+L2 overall. Consider both thread engagement and total projection when specifying an assembly.

Polymer tip and hex-drive callouts

The source table gives B=1.4 mm and L3=0.9 mm for M2, B=1.6 mm and L3=1.5 mm for M3, and B=2.5 mm and L3=2 mm for M4. L3 spans the hex opening in the top view; confirm the matching tool on a formal drawing. Tip color and polymer composition are not guaranteed model by model.

Softer-contact applications

The supplier says the polymer tip can hold optical elements while avoiding direct hard-metal contact. That does not establish safe preload, mark-free use or long-term creep resistance. Check optic edge and coating, female-thread depth, contact surface and screw projection, and avoid excessive clamp force.

Material claim and missing engineering data

The 304 stainless claim has no accompanying certificate, and the polymer type and hardness are unnamed. Pitch, thread and dimensional tolerances, tightening torque, temperature and chemical ratings, pack quantity and performance testing are not supplied. The pale tip in one model photo reinforces the need to confirm the delivered appearance.

Selection checklist

Choose M2/M3/M4 and metal-body L1

Allow separately for protruding tip L2 and overall length

Check B, L3 and driver fit

Confirm polymer, contact load and actual tip color

To be confirmed

Pitch, thread class and dimensional tolerances

Polymer grade, hardness and color consistency

Torque, safe contact load and creep behavior

304 certification and pack quantity