Chipboard Screw

What a chipboard screw is

A chipboard screw is a countersunk wood screw made for particleboard and timber. Hobson lists these in its DRiLLX multi-use range as chipboard countersunk ribbed screws: a countersunk head with ribs under it, a Phillips drive, a coarse thread and Hobson's chipboard / treated pine point (code D in its part numbers), which Hobson says is designed for fastening chipboard or timber. They are listed to AS 3566 and made from hardened C1022 steel.

People search for them as chipboard screws, particle board screws, flooring screws and yellow tongue screws. They are used for cabinets, shelving, joinery, particleboard and chipboard sheet work and general timber work. Structural particleboard flooring is different: the flooring makers name a Type 17 screw of at least 10g x 50mm, and these screws are not that screw (see the flooring section below).

Chipboard screw sizes and lengths

The size is gauge and threads per inch: 8-9 is an 8 gauge screw (4.2mm across the thread) with 9 threads per inch, and 10-8 is a 10 gauge screw (4.8mm) with 8 threads per inch. By Hobson's definition both are coarse thread (up to 16 TPI), which Hobson says is generally used for timber.

A countersunk screw is measured from the top of the head, because the head sits in the board. As general practice, choose a length that passes through the sheet and well into the frame or part behind it.

Particle board flooring screws: what the flooring makers say

Structural particleboard flooring (yellow tongue) is laid to AS 1860.2 and the board maker's installation guide, and the fastener is set by that guide, not by the screw maker. Following it is not optional: use the fastener it names. Our particle board flooring page carries the Structaflor and EnduraFloor guides.

• •What the flooring makers name: for screw fixing to timber joists, Porta's Structaflor guide lists Type 17 countersunk self-drilling wood screws, at least 10g x 50mm for 19 and 22mm sheet and 14g x 65mm for 25mm sheet, and countersunk self-embedding head self-drilling screws (9g or 10g x 45mm) for steel joists. Laminex's EnduraFloor manual lists No. 10 x 50mm Type 17 countersunk self-drilling screws for timber composite joists (nails for hardwood, cypress and softwood joists) and No. 10 x 45mm countersunk self-embedding wing tip screws for steel.
• •Our chipboard screws are not those screws. They have Hobson's chipboard point, not a Type 17 point, and the 8 gauge screws are also below the 10g x 50mm minimum both guides list. For a structural particleboard floor, use the Type 17 screw (or other fastener) the board maker's guide names. For 19 and 22mm sheet on timber joists, the screw we supply is Hobson's Type 17 countersunk Torx screw, 10g x 50mm in Tykote, box of 500 (linked above as the Type 17 flooring screw). Hobson has no Type 17 countersunk screw at the 14g x 65mm Structaflor names for 25mm sheet, so we match that one on the quote.
• •Coating: EnduraFloor asks for screws that are zinc or cadmium electroplated with a yellow iridescent chromate conversion coating Type C to AS 1789 where the floor is exposed to the weather during construction. Hobson does not state that its zinc yellow passivate is that coating.
• •Spacing (Structaflor, 800mm wide sheet): 150mm centres along the sheet edges, 250mm in the body of the sheet (300mm for 600mm wide sheet), at least 10mm from square edges and 25mm from tongue and groove edges.
• •Glue as well: Structaflor says construction adhesive with the nails or screws is mandatory, as a continuous 5mm bead on each joist.
• •Quantity: Structaflor lists 40 fasteners per 3600 x 800 sheet on joists at 450mm centres and 32 at 600mm centres.

Zinc yellow and Dover White: where these screws suit

All our chipboard screws are zinc yellow passivate: zinc electroplate with an iridescent yellow conversion layer, about 5 microns thick. Hobson rates it as low corrosion resistance, recommended for low-corrosion environments or temporary fixing, so these screws are for dry, enclosed work: cabinets, shelving, joinery and other interior sheet and timber work.

They are not for decks, pergolas or other work exposed to the weather. Hobson's corrosion guide calls for stainless steel or hot dip galvanising where a fixing is exposed, and Hobson's self-drilling screw warranty covers its Class 3, Class 4, X9 and bi-metal screws, not zinc yellow. For decks and outdoor timber, see our Type 17 and decking screws.

The Dover White range has the head painted in COLORBOND Dover White (Hobson swaps the 9P in the part number for the colour code DW) for a white head on white surfaces.

How to drive chipboard screws

General practice, not Hobson instructions, except where Structaflor is named.

1. Fit a Phillips bit that fills the recess, in a screw gun, drill or impact driver. A bit holder adds reach and makes changing insert bits quick.
2. Hold the screw square to the sheet and keep steady pressure so the point starts cleanly and does not walk.
3. Drive the head flush with the surface. For particleboard flooring, Structaflor says to drive fasteners flush and punch them 2mm below the surface only immediately before sanding.
4. Stop as the head seats; driving on can strip the thread in the board.

Chipboard screws in Adelaide

Allmat supplies chipboard screws, driver bits and fixings to builders, carpenters, cabinet makers and joiners across Adelaide and South Australia. Add the screws to a quote with your sheet, timber or the rest of your list and we will price the lot.

Questions