Tools and materials

Fasteners and washers

Screw drives

Philips head and Pozidriv

✎ This article/section is a stub — some half-sorted notes, not necessarily checked, not necessarily correct. Feel free to ignore, or tell me about it.

The Phillips screw drive (often marked PH on screw bits), designed in 1932, was once the typical variant of the cross-shaped screw.

They were designed as an improvement to flat-head (slotted) screws. Flat head would cam out fairly easily, slip, need some alignment. ...more so around smaller screws and around power tools.

At the same time, phillips too will cam out fairly easily (more so if you get the wrong size), a little more so than most other cross-style designs designed since. (There is a theory this was intentional, to avoid overfastening, or save power tools / bits where there was no torque-based ratcheting, but neither of these seems true(verify))

Pozidriv (often marked PZ on screw bits), designed around 1960s, is a different design, from a different company.

Compard to PH, PZ will do a little more torque before it cams.

To this day is often confused with PH. You can identify

• PZ bits/heads by the extra protrusions things between the four main wings
• PZ screws by marker slits between the actual slots

It seems many types of modern DIY screws are pozidriv, though there are also modern cases that use Philips.

On using the wrong size PH or PZ

For both, size 2 seems to be most common for around-the-house screws, and sometimes a 3 for noticeably beefier screws.

On mixing PH an PZ

If you need minimal torque, then you can get away with treating PZ as PH, or PH as PZ, but neither is ideal.

• PH driver in PZ screws will loosely fit, but slip and cam out once you try to apply more torque, damaging screws and your bits.

• PZ drivers in PH screws will generally not go as deep, so also cam out more easily

https://en.wikipedia.org/wiki/List_of_screw_drives#Phillips

See also

https://en.wikipedia.org/wiki/List_of_screw_drives

Tools

Saws

Miter saw

A miter is and angled joint[1].

A miter saw (or mitre saw) helps such joints -- and anything else that is served by well controlled angles

Classically this was mechanical:

• miter box

wood with slits that guide 90 and 45 degree angles

to use a regular handsaw in

• the most basic thing you could call 'miter saw' is a handsaw guided by a mechanical mount

(and replacable blade)

preferable in that miter boxes tend to degrade with use, so this is more reusable and more precise

Power miter saws are the variants that are motorized, mainly:

• standard miter saw

brings down a saw head, at a controlled angle.

(a chop saw is this without the angle control, always cutting right, 90 degree angles)

• compound miter saw

adds tilt of the head

(sometimes the basic rotation may be a little more aribitrary/controlles than in a basic variant)

Options / details:

• sliding miter saw (on a compound or standard miter saw)

sawblade extends on a sliding rail, rather than only being brought down

can deal with somewhat larger boards

• ability to angle to both sides rather than one (and, less commonly, to tilt to both sides)

easier to do certain cuts readjusting the saw rather repositioning than the workpiece

• LED/laser

a little more precision

Because this is a collection of features realized in different combinations

some may be unique to areas (or industries)

and may have specific names in some areas of the world that they do not have in others.

Circular saw

Sort of like a table saw without a table.

Generally for wood, though variations for e.g. metal and concrete may vary in design, not just mounting a different blade.

Tool materials

https://en.wikipedia.org/wiki/Miter_saw