Secure Ring
Secure rings that knock down over a hex bolt or nut so it cannot be undone, in 316 stainless and galvanised steel.
About the Secure Ring
Secure rings are steel rings you knock down over the hex head of a bolt, nut or screw so no spanner or socket can turn it, for a permanent tamper proof fixing on signs, bins, seating, playgrounds and gates. They come in 316 stainless for DIN hex bolts and nuts from M6 to M16, and mechanically galvanised for AS hex bolts and nuts from M6 to M20 and for 5/16 and 3/8 inch hex head screws, with the install tool for the screw rings. Choose the ring above; the guide below covers matching the ring to the hex size and fitting.
Also called security rings or anti tamper rings.
Features
- 316 stainless, M6 to M16 (AF10 to AF24), to suit DIN 931, 933 and 934
- Mechanically galvanised, M6 to M20 (AF10 to AF30), to suit AS 1110 and AS 1111
- Mechanically galvanised for #10-12 (5/16 AF) and #14 (3/8 AF) hex screws
- Zinc plated installation tool for 1/4, 5/16 and 3/8 AF hex screws
Applications
- Permanent tamper proof bolts on signs, bins and seating
- Playgrounds, gates and public fittings
What a secure ring does
A secure ring is a short steel ring that you place over the hex of a fastener that is already tightened, then hit down with a mallet. It deforms over the hex and leaves a round, smooth cover that a spanner or socket cannot grip, so the bolt, nut or screw cannot be undone with standard tools. Hobson describes secure rings as permanent tamper-proof security for installed bolts, nuts and screws.
Because they are permanent, fit them only once the fixing is final. Common uses are signs, fences and gates, playground and street furniture, public toilets and facilities, and anything worth stealing that is held by ordinary hex bolts, nuts or hex head screws. A ring adds no strength: the bolt or screw underneath still carries the load, so choose and tighten it for the job first.
Match the ring to the hex size, not just the thread
The ring has to suit the size across flats (AF) of the hex it covers, and that is not always the same for one thread size. DIN 931 and 933 bolts and DIN 934 nuts have a 17mm hex at M10 and 19mm at M12; AS 1110 and 1111 bolts and AS 1112 nuts have 16mm and 18mm. So the 316 rings (made for DIN) and the galvanised rings (made for AS) differ at M10 and M12. At M6, M8 and M16 both suit the same hex: 10, 13 and 24mm.
For hex head screws, go by the screw's hex: the 5/16 inch ring for #10 and #12 screws and the 3/8 inch ring for #14, as Hobson lists them. If in doubt, measure the hex on your screws.
Secure ring sizes
Every secure ring and the install tool we carry. Select a row to open it in the selector.
Hex AF = the size across flats of the hex the ring fits, from Hobson's product descriptions. D and H are the ring dimensions lettered on Hobson's data sheet drawings (250616DS, 2604091DS, 260519DS), in mm. Pack is the minimum order. Tap a number to show it in the selector above.
| Range | Size | Hex AF | Fits | D (mm) | H (mm) | Pack |
|---|---|---|---|---|---|---|
| 316 stainless, for DIN bolts and nuts | ||||||
| 316 stainless, for DIN bolts and nuts | M6 | 10mm | M6 DIN 931 bolts, DIN 933 set screws, DIN 934 nuts | 16 | 6.8 | Packs of 50 |
| 316 stainless, for DIN bolts and nuts | M8 | 13mm | M8 DIN 931 bolts, DIN 933 set screws, DIN 934 nuts | 20 | 8.0 | Packs of 50 |
| 316 stainless, for DIN bolts and nuts | M10 | 17mm | M10 DIN 931 bolts, DIN 933 set screws, DIN 934 nuts | 27 | 10.0 | Packs of 50 |
| 316 stainless, for DIN bolts and nuts | M12 | 19mm | M12 DIN 931 bolts, DIN 933 set screws, DIN 934 nuts | 34 | 12.0 | Packs of 25 |
| 316 stainless, for DIN bolts and nuts | M16 | 24mm | M16 DIN 931 bolts, DIN 933 set screws, DIN 934 nuts | 41 | 16.0 | Packs of 10 |
| Mechanically galvanised, for AS bolts and nuts | ||||||
| Mechanically galvanised, for AS bolts and nuts | M6 | 10mm | M6 AS 1110 bolts, AS 1111 set screws, AS 1112 nuts | 16 | 6.8 | Packs of 50 |
| Mechanically galvanised, for AS bolts and nuts | M8 | 13mm | M8 AS 1110 bolts, AS 1111 set screws, AS 1112 nuts | 20 | 8.0 | Packs of 50 |
| Mechanically galvanised, for AS bolts and nuts | M10 | 16mm | M10 AS 1110 bolts, AS 1111 set screws, AS 1112 nuts | 27 | 10.0 | Packs of 50 |
| Mechanically galvanised, for AS bolts and nuts | M12 | 18mm | M12 AS 1110 bolts, AS 1111 set screws, AS 1112 nuts | 34 | 13.0 | Packs of 25 |
| Mechanically galvanised, for AS bolts and nuts | M16 | 24mm | M16 AS 1110 bolts, AS 1111 set screws, AS 1112 nuts | 41 | 17.0 | Packs of 10 |
| Mechanically galvanised, for AS bolts and nuts | M20 | 30mm | M20 AS 1110 bolts, AS 1111 set screws, AS 1112 nuts | 51 | 21.0 | Packs of 10 |
| Mechanically galvanised, for hex head screws | ||||||
| Mechanically galvanised, for hex head screws | #10-#12 | 5/16 inch | 5/16 inch hex head screws (#10, #12) | 19 | 9 | Packs of 100 |
| Mechanically galvanised, for hex head screws | #14 | 3/8 inch | 3/8 inch hex head screws (#14) | 19 | 9 | Packs of 50 |
| Install tool for the screw rings | ||||||
| Install tool for the screw rings | 1/4-3/8 | 1/4 to 3/8 inch | Setting the 5/16 and 3/8 inch screw rings | Packs of 10 | ||
Fitting secure rings on bolts and nuts
- Install and tighten the bolt or nut as its maker specifies.
- Place the secure ring over the bolt head or nut, centred on the hex.
- Hit the top of the ring with a mallet (Hobson's Did You Know sheet says a rubber mallet). This drives the ring down onto the hex and deforms it.
- Keep hitting until the ring sits flush on the fixing.
Fitting secure rings on hex head screws
- Install the screw as its maker specifies.
- Place the ring over the screw's hex head, centred on the screw.
- Put the install tool (IRSMSZTS-037, for 1/4, 5/16 and 3/8 inch hex heads) on top of the ring, over the hex.
- Hit the top of the tool with a mallet. This drives the ring onto the screw and deforms it at the same time.
- Keep hitting until the ring covers the hex and is flush with the material surface.
316 stainless or mechanically galvanised: which finish for where
- 316 stainless rings: Hobson says they can be used with 304 and 316 hex bolts. Use them on stainless fixings, and where Hobson's corrosion guide calls for stainless: sheltered or exposed fixings in the sea spray zone (304 or 316) and anything within 2m of a pool edge (316).
- Mechanically galvanised rings for bolts and nuts: Hobson describes the coating as for external use, with similar corrosion resistance to hot dip galvanising. Hobson's finish comparison rates mechanical galvanising (MGAL) in general at 50 microns with high corrosion resistance; the secure ring sheets give no coating thickness. They can be used over zinc plated and plain finish bolts.
- Mechanically galvanised rings for screws: Hobson rates them suitable for Class 4 and X9 coated screws.
- The ring does not upgrade the fastener under it. A zinc plated bolt is still an indoor finish; outdoors, start with a hot dip galvanised or stainless bolt that suits the site.
Secure rings in Adelaide
Allmat supplies secure rings, security screws, shear nuts and the bolts and nuts they cover to councils, sign makers, fencers, maintenance crews and builders across Adelaide and South Australia. Add the rings to a quote with the fasteners, and we will price the lot.
Secure rings for signs, fences and public places
Secure rings, security screws, shear nuts and the bolts they go on are available to order from Allmat for councils, sign makers, fencers, playground and facility maintenance crews, builders and trade across Adelaide and South Australia. Order through Allmat, we pick and pack it, then click and collect from the Allmat yard or have it delivered to site.
Goes with
Questions
What is a secure ring?
A steel ring you knock down over the hex of a tightened bolt, nut or hex head screw. It deforms over the hex and leaves a smooth round cover that a spanner cannot grip, so the fastener cannot be removed with standard tools.
Which secure ring do I need for an M10 or M12 bolt?
It depends on the hex. DIN bolts and nuts have a 17mm hex at M10 and 19mm at M12: use the 316 rings. AS bolts and nuts have 16mm and 18mm: use the mechanically galvanised rings. Measure across the flats if you are not sure.
How do you fit a secure ring?
Tighten the fastener first, centre the ring over the hex and hit it down with a mallet until it sits flush. On hex head screws, put the install tool on top of the ring and hit the tool instead.
Can secure rings be removed?
Hobson describes them as permanent tamper-proof security, so treat them as permanent and fit them only once the fixing is final.
Do I need the install tool?
For the 5/16 and 3/8 inch screw rings, yes: Hobson's instructions set them with the IRSMSZTS-037 install tool and a mallet. The rings for bolts and nuts are set with a mallet alone.
Are secure rings suitable outdoors and near the coast?
The mechanically galvanised rings are made for external use. In the sea spray zone, or within 2m of a pool, Hobson's corrosion guide calls for stainless: use the 316 rings on stainless bolts.
Where can I buy secure rings in Adelaide?
Order through Allmat. Order ahead by phone on 1300 03 03 63 or send your list for a quote, then click and collect from 25 Kapara Road, Gillman, or have them delivered to site.
Secure Ring: sizes and finishes we supply
14 lines by type and finish. Pick one above for its product code and pack sizes.
| Type | Finish | Sizes | Lines |
|---|---|---|---|
| Secure | Mechanical Galvanised | M6, M8, M10, M12, M16, M20 | 6 |
| Secure | 316 Stainless | M6, M8, M10, M12, M16 | 5 |
| Secure | Mechanical Galvanised | #10-#12, #14 | 2 |
| Install tool | Zinc Plated | 1/4-3/8 | 1 |
Data sheets and documents
The documents for the product you choose are listed with the selector above. Here is every Secure Ring document from Hobson Engineering.
All Secure Ring documents (11)
Data sheets and technical data (5)
Did You Know flyers (2)
Need them in bulk?
Add the sizes you need to your quote, or send us your list and we’ll price the lot and supply it with the rest of your order.
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