Home / Products / Plastics / Self-Tapping Screws / TMS

TMS

SELF-TAPPING SCREWS FOR THERMOSETS

Our TMS self-tapping screws are fasteners for thermoset plastics. Their particular characteristics make these screws particularly suited to this type of material. The cutting crest, contoured root and particular form of the threading itself allow for both low install torque and high pull-out force. Their effective chip removal ensures minimal breaking forces, making them an ideal solution to the problems that are so typical of installing self-tapping screws in thermoset materials.

Technical data

SPECIAL CUTTING CREST

Removes 60-80% of the material cut in order to make the threading. Reduces install torque. ·Reduces radial pressure.

SPECIAL CONTOURED ROOT

Ample chip cavities. Reduces radial force. Reduces install torque. Increased pull-out force.

SPECIAL SHAPE OF THREAD TOOTH

Reduces radial force. Maximized support surface. High pull-out force. High clamping force. High twist-out force.

Standard material: BS 3111 9/2 steel. Surface hardness 390 HV. Core hardness 340-380 HV.
Other materials and surface features available upon request.

BENEFITS

  • Minimizes the forces applied to thermoset plastics.
  • Ample margin of safety between installation torque and pull-out force.
  • Suited to all types of thermoset plastics.
  • May be used with thermoplastic resins with high filler content.

DESIGN GUIDE

Preparing the bore

The shape of the boss depends on the following factors:

  • Type of thermoset used;
  • Material density;
  • Amount and type of filler.

Because of these variables, the figures below are to be considered to be merely estimates of the lower and upper thresholds.

INSTALLATION

RECOMMENDED INSTALL TOOL SPEED

Installation speed is important because speeds that are too high can destroy the material in which the screw is being installed. We recommend a maximum speed of 600 RPMs.

Ta = Ti + 0.5 (Tp – Ti)

Ta: assembly torque.
Ti: installation torque or torque to cut plastic.
Tp: pull-out torque from the plastic boss.

This formula allows for an ample margin of safety in the mechanical resistance of the joint.

Sectors of use

Automotive

Home appliances

TMS

SELF-TAPPING SCREWS FOR THERMOSETS

Download the technical specifications

Here you can get a PDF with the product’s full technical specifications.

Download