Self-Tapping Blind Threaded Inserts In 316 Stainless Steel For Marine Use

Product Description

Self-tapping threaded inserts are a useful way to achieve a strong, permanent metric thread in soft materials such as fibreglass or wood – ideal for many situations on boats and yachts where often, only single-sided access is available. 

For installation, a suitably sized hole is drilled into the wood or fibre-glass (more details provided in our installation guide).  The insert is then screwed into the hole, self-tapping its own thread.  When installing these 316 stainless inserts in fibre-glass the size of the pilot hole can be quite critical, and it is desirable to test first on an unimportant area of scrap piece of material.

For drilling and installing these self-tapping inserts we have especially made guide jigs to suit each size of insert, available for purchase from our website.

The external thread will self-cut into a pre-prepared hole in a similar way a wood screw does providing a metric thread.

Blind self-tapping inserts can be used in applications where any fluid ingression along the internal thread could be an issue.

The head of the insert is shaped to sit fully flush once correctly inserted in order that it blends in with the existing area. Below the head is a recess to provide a space for sealant to squeeze into when a watertight fit is required, please see our separate guide below on installation procedure:

• Installation guide - quick link <here>
• Youtube video installation - quick link <here>
• Choice of sizes
• Drill & Installation Guide Jig Available <here>
• Solid 316 stainless steel construction
• Provides strong permanent metric thread
• Suitable for marine environments
• Manufactured in the UK

For suitable drilling sizes please do watch our installation video guide.  For a quick reference to core measurements and likely drilling sizes though we have provided the information below as a rough guide:

Insert Size M4

Outside diameter 5.96mm.  Core diameter 4.9mm.  Drill for soft materials 5.0mm.  Drill for harder materials 5.5mm

Insert Size M5

Outside diameter 7.95mm.  Core diameter 6.86mm.  Drill for soft materials 7.0mm.  Drill for harder materials 7.5mm

Insert Size M5 Heavy-Duty

Outside diameter 9.89mm.  Core diameter 8.7mm.  Drill for soft materials 9.0mm.  Drill for harder materials 9.5mm

Insert Size M6

Outside diameter 8.95mm.  Core diameter 7.6mm.  Drill for soft materials 8.0mm.  Drill for harder materials 8.5mm

Insert Size M6 Heavy-Duty

Outside diameter 11.95mm.  Core diameter 9.82mm.  Drill for soft materials 10.0mm.  Drill for harder materials 11.0mm

Insert Size M8

Outside diameter 11.95mm.  Core diameter 10.15mm.  Drill for soft materials 10.2mm.  Drill for harder materials 11.0mm

Insert Size M8 Heavy-Duty

Outside diameter 13.98mm.  Core diameter 11.65mm.  Drill for soft materials 12.0mm.  Drill for harder materials 13.0mm

Insert Size M10

Outside diameter 13.98mm.  Core diameter 11.75mm.  Drill for soft materials 12.0mm.  Drill for harder materials 13.0mm

Please take these drill sizes as a rough-guide.  If you are unable to get the fit that you want with these metric drill sizes, please also consider imperial sizes that may give other suitable alternative diameters (1 inch = 25.4mm)