Wood screws

Wood screws are preferred connectors in wood work spaces. They are strong, and allow connections to be made between parts made from solid wood, as well as sheet goods such as MDF and plywood. They eliminate the need for complex joinery. They have uses from the start to finish of a build, from jig and form construction through to mounting hardware and trim.

Screws are available in a variety of metals: aluminum, brass, silicon bronze and stainless steel. While there can be reasons for using something other than steel, including non-magnetic, corrosion resistance and decorative attributes, steel screws are the most useful for wood projects. Attributes include affordability, availability in a range of shapes and sizes, durability and strength.

Drywall screws are used by many wood workers. These are made from a relatively hard steel, allowing them to be driven in quickly, without pilot holes. They are often chosen because they are inexpensive. Unfortunately, they are also brittle and may snap. For projects requiring strong connections, they are a poor choice.

Production screws are hardened with sharp and strong points and threads capable of penetrating hard woods and other materials, including some metals. Their heads and shanks can withstand high torque driving with a power drill or impact driver, and can withstand stresses commonly experienced in furniture. Unfortunately, they are not weather resistant. Deck screws are production screws that have been plated and/or coated to increase corrosion resistance.

Several types of heads are available. Pan heads have a low disc with a rounded, high outer edge with large surface area. Button or dome heads are similar to pan heads, but with a more rounded top. These are not commonly used. Round heads have a decorative dome-shaped head. These are not designed to be used structurally. Truss or mushroom heads are specifically designed to prevent tampering. Flat or countersunk heads are conical, with a flat outer face and a tapered inner face. It is designed to sink into the material. Oval or raised heads are decorative with a countersunk bottom and rounded top. Of these the countersunk head is the most common in woodworking. Where a large surface area is needed for structural purposes, a pan head is used, with or without a washer, to increase the area.

Screw head types
Screw heads: (a) pan, (b) dome (button), (c) round, (d) truss (mushroom), (e) flat (countersunk), (f) oval (raised head)

As a Canadian, I used Robertson screws when I built my first sailboat in 1962-3. There were two qualities that made these an appropriate choice: stick fit and cam-out resistance. Stick fit is the ability of the driver to hold onto the screw without human intervention. This frees a hand but, more importantly, it allows screws to be driven into hard-to-reach places. Cam out is a problem with Phillips screws, especially. When torque exceeds a screw’s capacity the driver will slip out of the head of the screw.

Star (aka Torx) drives offer the same advantages as Robertson drives. Since these are universally available in Norway, these are preferred drives for woodworkers willing to make rational choices.

Standard screws at Unit One are Heco TFT Woodscrews, which can be used for interior and exterior purposes. They are in corrosion class 4, made of herded steel.

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Heco TFT Woodscrew

Standard sizes are: (Torx 20) 4.0 x 30, (Torx 25) 5.0 x 40, 5.0 x 60, (Torx 30) 6.0 x 90 and 6.0 x 160.

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Heco TFT Woodscrew packaging.

Seeds: Prototype Hardwood Furniture

Currently, I am designing a new kitchen table. My mandate is to make one that is sufficiently high that it can also function as a kitchen work top suitable for a taller person (> 1800 mm). In terms of size, the following dimensions have been specified: Minimum/ maximum length = 1200 to 1400, width = 500 to 600, height = 1000 to 1100 (all in mm). Before being built, the height, especially, will be performance tested with respect to common kitchen tasks such as chopping, mixing and stirring. An electrically driven, height variable desk is available for testing purposes.

Notes:

  1. While not part of the current project, other work tops will be made to accommodate a shorter person (< 1700 mm).
  2. Patrick Sullivan in his 2017 video Designing and Building a Mini Workbench  suggests a workbench height of 43″ = 1100 mm. Admittedly, this is for woodworking, not cooking. The first 2m15s of this video should be watched by everyone with an interest in, or a need to undertake, physical work. https://www.youtube.com/watch?v=N2fNDxa2GIM
table heights
Heights of assorted chairs and tables in inches.  Approximate conversions Chairs: 18″ = 450 mm, 26″ = 650 mm, 30″ = 750 mm, 34″ = 850 mm. Tables: 30″ = 750 mm, 36″ = 900 mm, 42″ = 1050 mm, 48″ = 1200 mm. (Photo: from YouTube video by user Pablo 1499 (2013) Standard Height for Bar Stool Counter Top)

In addition, two chairs will be made. These will be ergonomically designed specifically for each occupant. In order to ensure that each chair is suitable, a prototyping chair will be made. This prototyping chair will be fully adjustable in several directions, and will also be available to ensure that any future chairs can also be made that accommodate the dimensions of any adult. If necessary, a separate prototyping chair for children can also be made.

At the present time, oak has been purchased for this build. However, it may be decided to use other materials. Part of the challenge is the extensive use of oak in the living room, and plans to make even more furniture in oak for that room. Ideally, a different type of hardwood, such as beech or birch, would be preferred in the kitchen.

The table is to placed adjacent to the kitchen windows, with the chairs beside each other so that each occupant can look outside through her/his own personal window. A variety of sights can be expected including birds feeding on sunflower seeds, post people delivering mail, ships sailing under Skarnsund bridge, and more.

 

Resources

This post has its origins in a couple of emails sent to real, living people. I have combined and changed them, just slightly, to protect the guilty. Many of the videos are related to DIY (Do It Yourself). As noted in an earlier post, one motto used by Unit One is “Do It Ourselves”, which emphasizes collective action to solve challenges that arise.  

Computing   Chris Barnat likes the same types of computers that I do. He is also interested in other aspects of modern technology, so both of his channels are enjoyable. Explaining Computers & Explaining the Future. If you watch enough Chris Barnat videos, you will learn about a “single board computer” called Raspberry Pi. I work with single board computers because I think they are fun, small and functional. They can also be frustrating. If I lacked a computer and didn’t have money to buy a more expensive one, I  would acquire a Banana Pi, Raspberry Pi or Tinker Board. If I had the money I would buy something more expensive, such as a Gigabyte Brix (my current first choice) or Intel NUC.

One of my main areas of interest is control systems, sometimes referred to as home automation, Internet of Things or physical computing. An Arduino combines low cost with ease of use, to make it an entry point for this type of computing.   Almost any computer can be used to program an Arduino board. You will need some electronic components to construct circuits.   1. Introductory Arduino  For further information, visit the Arduino website. To learn about physical computing watch the videos by Jeremy Blum,   2. Advanced Arduino   Sometimes people don’t know where to go to, after they have a basic understanding of the Arduino. In addition to the main website, Volts and Notes is a good source. It specializes in circuits for musical instruments, but also explains why things are done the way they are. Volts and Notes have three (3) videos that will help you make a transition from introductory to advanced user. a. Arduino on a breadboard b. Arduino as ISP c. Arduino on a protoboard – make it permanent.   Computing isn’t the only area where people can learn to be more capable.

Women workers in wood and metal  April Wilkerson. Originally April focused on home improvement through woodworking. Now she has expanded into other areas, such as welding. Dabin Orvar is a Swedish woodworker living in Portland, Oregon. Laura Kampf is a German woman woodworker and metalworker.

Male woodworkers that don’t talk down to people (that much).   Steve Ramsey’s channel, Woodworking for Mere Mortals, is probably the best place to start to learn woodworking. He is from Marin County, north of San Francisco. Worked as a graphic designer, but had woodworking as a hobby. Jeremy Fielding is one of my favourites. Personally, I would prefer him to Steve Ramsey because Jeremy has to work in confined spaces, and is into recycling. Jeremy, can be a little bit “special” for some people, just starting out.   John Heisz is an Ontario builder and woodworker. I like him because he has a lot of goodpractical advice. Here is his Home Improvement channel and his General Woodworking channel.

Advanced woodworking. People to watch after you have mastered the basics. Matthias Wandel is an Ontario woodworker. He likes to make a lot of complex things, including his own equipment, but also has a lot of good advice. Marius Hornberger is a German woodworker who likes to make equipment.

This weblog post was originally written 2017-10-11 and saved at 10:01. It reflects views held at that moment in time, which have changed since then.