4mm Machine Screws/Bolts M4 x 10mm A2 Stainless Steel Pozi Pan Head Mch Screw (10 Pack) Free UK Delivery

Product Information

Phillips and slotted drives are the two main types. Some are a combination that works for either type. Also, the given length for the screws is the length that is usually buried in the wood or in other materials. The head of the raised screw is usually not included. Therefore, the screw size is determined by the gauge and the length. Explanation on Metric Screw Sizes

Although technically you can use a Phillips driver on a Pozidrive screw and vice versa, their not really designed to fit and under torque load (when you are screwing the screw in) in pretty much all situations it will slip and damage the head of the screw making it difficult to either screw in the screw or remove it, so it’s always best to use the right tool for the job. There are a range of acronyms and letters that you often find on screw boxes or in their online descriptions. Here is a summary of the most common, and what they mean:

Imperial Screw Sizes Explained

The gauge indicates the diameter. A larger number means a bigger diameter, whereas a smaller number means a smaller diameter. For example, a number 3 is smaller than a number 11. Structural wood screws have an unthreaded shaft and coarse threads. Structural wood ones may appear similar to wooden ones, but they are more durable. Sheet Metal Therefore, a size 12 screw is larger than a size 4. The screws from gauge 6 and above have twice the diameter’s head.

Resin is obviously a great way forward as it holds well without creating stress, but it’s much more work and the nuts don’t look as neat as a screw or bolt head. All these are the different fastener categories. However, we will focus on screws. There are various types of screws available in the market.See what they have at the store screw/length wise, stainless steel is best of course. You could even consider structural timber screws, if you can get a wall plug big enough for them. They are long, have flanged heads and designed for outdoor use, just a thought (Have a look at what I mean at screwfix…).