BLIND SELF-TAPPING THREADED INSERTS (SERIES STB)

Blind threaded inserts offer standard metric internal threads with 30 degree inclusive form coarse pitch self-tapping external threads. We would recommend blind self-tapping inserts (Series STB) for use in applications where fluid ingression along the internal thread could be an issue. The coarse thread of this type of insert is designed to give more strength, particularly when used on composite materials or softer materials such as wood, fibreglass or plastics. We can custom manufacture inserts to drawing, and our standard range spans M2 to M20 sizes in marine grade stainless steel 316 (A4) or stainless steel 303 (A2) - request a quote today.

We also produce a more robust, heavy duty version of the popular M6, M8 and M10 sizes, with a length of 30mm, to give more external surface area and a deeper, courser thread than the standard inserts.  It will also provide more grip strength and is suited to heavier duty applications and are again, available in marine grade stainless steel.

The insert has a 45 degree shoulder with an undercut to seat it when fully inserted, this provides an area where a sealant or bonding agent can be applied to prevent any fluids passing along the external surface of the insert into the host material or the area behind the insert. The lead-in is chamfered at 10 degrees, with three notches milled into it, to help remove host material, provide a sharp cutting edge and assist keeping the insert parallel on insertion. 

Praise For Our Blind Self Tapping Inserts:

"These inserts have been a marvellous find for us. They do the job superbly, save a lot of time over the previous method of installation and the shipwrights find them very easy to use. Keep up the good work."

 

Blind threaded inserts have an internal and external thread and are self-cutting, and are supplied in a choice of steel, stainless steel 303 or marine grade stainless steel 316.

This range of inserts is manufactured to the dimensions below:

 

STB Series Blind Self-Tapping Inserts Size Range

Part # Inside Thread Length ID OD OD Thread Type & Pitch Cutting Relief
M4173 M2 7mm M2 x 0.4mm 4.0mm 30 degree flank self tapping P=1.00mm 3 x milled notch
M4604 M3 8mm M3 x 0.5mm 5.0mm 30 degree flank self tapping P=1.00mm 3 x milled notch
M3398 M4 9mm M4 x 0.7mm 6.0mm 30 degree flank self tapping P=1.25mm 3 x milled notch
M3399 M5 10mm M5 x 0.8mm 8.0mm 30 degree flank self tapping P=1.5mm 3 x milled notch
M3320 M6 12mm M6 x 1.0mm 9.0mm 30 degree flank self tapping P=1.75mm 3 x milled notch
M3796 M6 30mm M6 Heavy Duty 18.0mm 30 degree flank self tapping P=3.0mm 3 x milled notch
M3400 M8 15mm M8 x 1.25mm 12.0mm 30 degree flank self tapping P=2.0mm 3 x milled notch
M3779 M8 30mm M8 Heavy Duty 20.0mm 30 degree flank self tapping P=3.0mm 3 x milled notch
M3318 M10 20mm M10 x 1.5mm 14.0mm 30 degree flank self tapping P=2.5mm 3 x milled notch
M3797 M10 30mm M10 Heavy Duty 20.0mm 30 degree flank self tapping P=3.0mm 3 x milled notch
M3319 M12 25mm M12 x 1.75mm 16.0mm 30 degree flank self tapping P=2.75mm 3 x milled notch
M3725 M16 35mm M16 x 2.0mm 25.0mm 30 degree flank self tapping P=3.50mm 3 x milled notch
M3741 M20 40mm M20 x 2.5mm 30.0mm 30 degree flank self tapping P=3.50mm 3 x milled notch

Materials

• Steel • Stainless Steel 303 (A2) • Marine Grade Stainless Steel 316 (A4)

Course Threads

The coarse thread of this type of insert is designed to give more strength, particularly when used on composite materials or softer materials such as wood, fibreglass or plastics.

Size Range

Our blind self tapping inserts range from M2 through to M20 sizes.

Cutting Relief

The insert has three notches milled into it, to help remove host material and assist keeping the insert parallel on insertion.

Heavy Duty Inserts

We also produce a more robust, heavy duty version of the popular M6, M8 and M10 sizes, with a length of 30mm, to give more external surface area and a deeper, courser thread than the standard inserts.

Custom Manufacture

Can't see what you need? We can manufacture our inserts to customer drawing - call 01536 461140 and speak to our team.

Insert Installation Guide

We've been asked by many of our customers for advice on the installation of our Blind & Through Tapped Self-Tapping Inserts into various applications such as wood, soft plastics, fibreglass and acrylics. Download our guide. Please note, all recommended hole sizes are entirely advisory and should be treated as such. This advice is intended as a guide rather than a definitive method of use as all applications are different. The use of these inserts depends on the host material and application. We always advise that you experiment a little first. Technifast are not responsible for any damage caused in the course of using our inserts.

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