Screwdriver bit size chart (free printable PDF)
Which driver bit drives your screw? This chart maps each screw gauge to its Phillips bit size (PH0–PH4) — a #8 screw takes a PH2 — with a Phillips size reference and a quick way to tell the common drive types apart. Using the right, well-fitting bit is the single best way to stop a screw head stripping. Download the free printable PDF or print it from the page.
Screwdriver bit size chart
| Screw gauge | Phillips bit | Also written |
|---|---|---|
| #4 | PH0 | #0 Phillips |
| #5, #6, #7 | PH1 | #1 Phillips |
| #8, #9, #10 | PH2 | #2 Phillips |
| #12, #14 | PH3 | #3 Phillips |
| 5/16" and up | PH4 | #4 Phillips |
PH2 is the everyday size — it fits #8–#10, the most common wood and construction screws, so it’s the bit that lives in most drivers. “PH2” and “#2 Phillips” mean the same thing. Using the size that fully seats in the head is what stops the bit slipping and rounding the screw.
whatdrillbit.com
How to read it
Find your screw gauge on the left; the middle column is the Phillips bit to drive it. Most everyday screws are #8–#10, so a PH2 covers the bulk of jobs — keep smaller (PH1/PH0) and larger (PH3) bits on hand for the ends of the range. Don’t know your gauge? Measure the screw and check the screw size chart.
This chart is for Phillips — the most common drive. If your screw isn’t a plain cross, jump to the drive-type quick-ID below to identify Pozidriv, Torx, square or slotted.
The right bit is the #1 way to stop a stripped screw. A wrong-size or worn bit slips under load and rounds the head (“cam-out”). Match the bit, push hard, slow down.
Why your screw keeps strippingPhillips bit sizes (PH0–PH4)
| Phillips bit | Also | Fits screws | Typical use |
|---|---|---|---|
| PH0 | #0 Phillips | #4 and smaller | Small hardware, electronics, tiny hinges |
| PH1 | #1 Phillips | #5–#7 | Light-duty; small woodworking, switch plates |
| PH2 | #2 Phillips | #8–#10 | The everyday size — most wood & construction screws |
| PH3 | #3 Phillips | #12–#14 | Larger, heavier screws; framing hardware |
| PH4 | #4 Phillips | 5/16" and up | Heavy structural; uncommon in DIY |
Read it either way: know the screw and get the bit above, or read a bit’s stamp (PH2, #2) and see what it drives. Ranges overlap a little at the edges — if a bit rocks or bottoms out before seating, step a size the other way.
Telling the drive types apart
A quick way to identify what’s in your hand. The one people genuinely mix up is Phillips vs. Pozidriv — they look almost identical, but driving one with the other’s bit is a classic cause of cam-out.
| Drive type | How to spot it | Where you’ll see it |
|---|---|---|
| PhillipsPH0–PH4 | Four-point cross with tapered walls. Designed to cam out (slip) under high torque, so it's the most strip-prone. | The default on most everyday wood and general-purpose screws. |
| PozidrivPZ1–PZ3 | Looks like Phillips but has a second, shallower cross at 45° plus small radial tick-marks on the screw head. Not interchangeable with Phillips — a Phillips bit sits loose and cams out. | Common on European and imported hardware and flat-pack furniture. |
| Torx / starT10–T40 | Six-pointed star. Sized by T-number (T25 is common). High grip, strongly resists cam-out. | Modern deck, construction and structural screws. |
| Square / RobertsonR0–R3 (#0–#3) | Square recess. Grips hard and the screw sticks to the bit; often colour-coded by size. | Pocket-hole and cabinet screws, especially in North America. |
| Slottedflat blade | A single straight slot. Can't self-centre and slips easily, so it's fading from structural use. | Traditional and decorative hardware; some electrical. |
Phillips vs. Pozidriv: a Pozidriv head has extra fine lines at 45° and small tick-marks around the recess; a Phillips is a plain cross. When in doubt, a bit that rocks or won’t seat fully is the wrong type — stop before you round it. Torx (the six-point star) is sized by T-number, e.g. T25 on many deck and construction screws.
Common questions
What size Phillips bit for a #8 screw?
A #8 wood screw takes a PH2 (also written #2) Phillips bit — the everyday size. The same PH2 bit also fits #9 and #10 screws, which is why it's the one that lives in most drivers. For a #6 screw drop to a PH1; for a #12 or #14, step up to a PH3.
What is a PH2 screwdriver?
A PH2 is a #2 Phillips driver bit — the most common Phillips size. It fits #8 to #10 screws, the everyday wood and construction gauges. "PH2" and "#2 Phillips" are the same thing; the number is the Phillips point size, not the screw gauge.
How do I tell Phillips from Pozidriv?
Look at the screw head. A Phillips recess is a plain four-point cross. A Pozidriv has that cross plus a second, shallower set of lines at 45° and small tick-marks radiating from the centre on the screw's face. They're not interchangeable — a Phillips bit sits loosely in a Pozidriv screw and cams out, and vice versa — so match a PZ bit to a PZ screw. Pozidriv is common on European and imported hardware.
Does using the right driver bit stop screws stripping?
It's the single biggest factor in stopping a stripped (cammed-out) head. A bit that's the wrong size or worn doesn't seat fully, so it slips under load and rounds the recess. Use a fresh bit of the correct size and type, push firmly, and slow down as the head seats. (A stripped hole in the wood is a separate problem — see the screw-stripping guide.)
Gear for this job
As an Amazon Associate, WhatDrillBit earns from qualifying purchases.
Where these numbers come from
The screw-gauge → Phillips mapping is the standard reference used by driver and fastener suppliers (McFeely’s and agreeing sources); PH2 for #8–#10 is universal. The drive-type notes are general identification guidance. Sizes overlap slightly at the edges of each range — the real test is which bit seats fully in the head without rocking.
Bit-to-screw fit varies a little by manufacturer and screw style. The reliable check is physical: the bit should seat fully and not rock. If a Phillips bit feels loose, the screw may be Pozidriv — match the bit type before you drive.