Intermediate Phillips Sizes?

[Lesserstore]

Every now and again I will come across Phillips screws that seem to be in between standard sizes, most of the time it is too big for a #0, but too small for a #1, and occasionally the same thing happens with a screw being between #1 & #2. With some very cheap modern hardware I blame it on poor manufacturing, but I also encounter it with old US made stuff. Were/are there any custom Phillips sizes that only manufacturers used?

 

[DHCrocks]

maybe its a pozidriv ? they look like a phillips but are not and if you use the wrong screwdriver the fitment is terrible.

 

[neophyte]

There are a bunch of different “cross-head” screw designs which are similar buy not quite the same, and various cross head drivers will work, won’t work, or only sort of work depending on the design of the screw head and the driver.
Phillips is the standard cross head design used in the USA.
Pozidriv is the standard cross head screw used in Europe. Nowadays plenty of European items get sold in the USA, so running into Pozidriv screws isn’t uncommon(ie. Ikea)
Supadriv which is a modification of the pozidriv design. I’m not dure whether I’ve ever actually seen these or whether they just get mistaken for Pozidriv.
Frearson / Reed and Prince, which are sometimes found in boat biilding and marine use amongst other things.
JIS( ie. Japanese Industrial Standard) which are found used on Computers, other electronics, and items from Japanese manufacturers.

There are several other designs that are less common as well.
Newer cross head drivers are better designed to deal with the non Phillips screws.
If you try using an older Phillips driver design on one of the other screws such as JIS or Pozidriv you’re very likely to cam the screw head out.

 

[Dave455]

If a screw isn’t a Phillips, there will usually be some additional marking to indicate this. JIS (which is a type of Phillips) can be identified by an additional dimple on the screw head. You will find these on many Japanese items.

A regular Phillips won’t fit well. the driver will be a little too fat. The current JIS profile has changed, and is interchangeable with a normal Phillips.

Pozidriv is found on British, or European, stuff (except aircraft). You can identify these by the additional star marking on the screw head.

A Phillips driver will fit, but not very well (it will seem like a size too small, and won’t work well). The only solution here is a Pozidriv screwdriver, but American manufacturers are poor at offering these.

You might also find Reed and Prince. These look like a very slender Phillips. They are actually the oldest of the profiles, and are generally used in boatbuilding!

 

[RoundedNut]

There are multiple "cross recess" designs but what you are noticing is likely just that the Philips recess screw was a very bad idea. Here are some things to keep in mind:

Screws of wildly differing head sizes may use the same Philips drive size. For example, small 1/4" long screws in computers/electronics require a #2, just like 3" long construction screws. So there is a varying amount of depth that the drive tip will sink into these screws.

Modern "Philips" drive tips are not actually Philips but conform to an international standard (ISO). One of the defining traits is a tip that is more blunt with straighter cross members. These work well on Philips screws but may not seem to fit exactly.

Like most manufactured items, there is a range or tolerance in dimensions. So some Philips tips may not fit very well in some screws. In particular, tips made by forging are different than those made by milling.

So ultimately, its a **** shoot, and I keep different makes of "Philips" bits per size on hand to see which one fits best.

 

[jgromada]

Pozidriv has a small dot on one part of the screw head. They are an improvement over standard Phillips, but torx is still better.

 

[Dave455]

Pozidriv has a small dot on one part of the screw head. They are an improvement over standard Phillips, but torx is still better.

Sorry, they don’t! That’s JIS you’re thinking of.

Pozidriv have an extra “star” marking!

Phillips on the left, Pozidriv on the right.

 

[Bubba Fett]

Read and enjoy this: https://www.instructables.com/When-a-Phillips-is-not-a-Phillips/

Then read this: https://www.instructables.com/When-a-Phillips-is-not-a-Phillips-Plus-So-Much-Mor/

Also, there are different standards for Phillips geometry, so an older Phillips #2 may have a sharper point than a newer Phillips #2. Most reputable brands should be following the new standard by now, which *should* be compatible with JIS, but there are still minute variations, depending on the manufacturer and their process.

 

[Lesserstore]

I should have been more specific. The things I have noticed cheap hardware that doesn't fit well are the free flashlights from HF. They also don't have any markings or the extra slots for pozidrive. The US made things that I have noticed it on is a rear sight screw on an old Daisy Model 25 bb gun, made between 1957-8, and a Craftsman box head 1/4" ratchet made between 1947-52. And the only other cross type screw available at that time would have been Reed and Prince and these screws are too small for it.