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Z Drill Size

Tom Woodward

Senior reporter

★★★★★5.0

500+ views

Today

6 min read

Looking for the best z drill size in March 2026? We reviewed 8 popular options from brands like MORSE, NELOMO, Magnetic, Useful, General, Morse and compared them on the things that matter most: build quality, comfort, ease of use, durability, and overall value. In this guide, you’ll find our top picks for different needs and budgets, plus a quick breakdown of what to look for before you buy. If you want a z drill size that performs well and holds up over time, this shortlist will help you choose with confidence.

Our Top Picks

Best Overall

MORSE CUTTING TOOLS Heavy Duty Large Plastic Wall Chart - Decimal Equivalents, Recommended Drill Sizes for Taps, and Useful Formulas

★★★★★★4.8

Size Range:21 1/4–33 3/4 inches

Material:Heavy duty plastic

Chart Dimensions:21 x 34 inches

Unit Systems:Imperial and metric

Accuracy:±0.001 inch

Mounting Options:Wall mountable

Massive 21×33‑inch .023‑in plastic chart offers complete drill tables, formulas, and decimal equivalents—durable, wall‑ready reference.

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Best Value

NELOMO 11.8” X 7.9” Toolbox Reference Card Toolbox Accessories Conversion Chart Card SAE Metric Ruler Standard Metric Conversion Charts Tap Drill Sizes Wrench Conversion Chart

★★★★★★4.6

Size Range:11.8 x 7.9 inches

Material:300 gram coated paper

Chart Dimensions:11.8 by 7.9 inches

Unit Systems:SAE and metric

Accuracy:±0.01 inch

Mounting Options:Toolbox pocket fit

Compact 11.8×7.9‑in laminated card packs extensive conversions, tap drills, and a built‑in ruler for toolbox convenience.

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Best Premium

Magnetic Tap & Drill Metric Conversion Chart - 8.5"x11" Guide to Metric Conversions Magnet - Tap Drill Size Chart - Comprehensive Metric Conversion Chart & Drill Hole Size Magnetic Chart

★★★★★★4.8

Size Range:8.5 x 11 inches

Material:Magnetic steel backing

Chart Dimensions:8.5 by 11 inches

Unit Systems:Imperial and metric

Accuracy:±0.001 inch

Mounting Options:Wall or tool magnet

Magnetic 8.5×11‑in chart sticks to steel, delivering color‑coded metric/inch tap data and pipe sizes for fast reference.

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Detailed Reviews

What to Look For Z Drill Size

Size Range

Diameter coverage from #0 to #80 (or metric 0.5–10 mm) lets users find the exact drill size for any standard fastener or tap.

Material

Heavy‑duty .023‑inch gauge plastic ensures rigidity, resists warping, and withstands frequent handling in shop environments while maintaining clear print visibility over years of use.

Chart Dimensions

Overall printed size (e.g., 21¼″ × 33¾″) determines readability from a distance and suitability for wall mounting or bench placement, ensuring users can view details without leaning over the workpiece.

Unit Systems

Includes imperial, metric, and pipe thread drill equivalents, letting users quickly convert across standards without separate references and reduces the risk of selecting an incorrect size during time‑critical jobs.

Accuracy

Manufactured to ±0.001″ tolerance, providing precise drill size identification for tight fit‑up and thread‑cutting applications, which is critical for achieving proper thread engagement and minimizing material waste.

Mounting Options

Pre‑punched mounting holes or built‑in slots facilitate secure wall or bench installation, keeping the chart visible and hands‑free during work.

by MORSE

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.8 / 5.0

MORSE CUTTING TOOLS Heavy Duty Large Plastic Wall Chart - Decimal Equivalents, Recommended Drill Sizes for Taps, and Useful Formulas

BEST OVERALL

The MORSE wall chart offers a massive 21 1/4 by 33 3/4 inch surface printed on thick .023 inch plastic. It lists drill sizes for inch, metric and pipe threads, provides decimal equivalents and handy formulas. The layout is clear and durable, making it a reliable reference for any workshop or classroom. It stays flat on walls and readable today.

Key Specifications

Size Range

✓21 1/4–33 3/4 inches

Material

✓Heavy duty plastic

Chart Dimensions

✓21 x 34 inches

Unit Systems

✓Imperial and metric

Accuracy

✓±0.001 inch

Mounting Options

✓Wall mountable

Reasons to Buy

✓Large readable surface
✓Durable .023 inch plastic
✓Complete drill tables
✓Includes formulas

Reasons Not to Buy

✗No digital version
✗Limited to wall use

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by NELOMO

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.6 / 5.0

NELOMO 11.8” X 7.9” Toolbox Reference Card Toolbox Accessories Conversion Chart Card SAE Metric Ruler Standard Metric Conversion Charts Tap Drill Sizes Wrench Conversion Chart

BEST VALUE

The NELOMO reference card fits neatly in a standard toolbox and delivers a dense collection of conversions, tap drill tables, wrench sizes and a built‑in ruler. Printed on 300 gram coated paper and sealed with a 12 micron PET + EVA laminate, it resists wear and moisture. Its compact 11.8 by 7.9 inch size makes quick lookup effortless during any job for professionals and hobbyists alike today.

Key Specifications

Size Range

✓11.8 x 7.9 inches

Material

✓300 gram coated paper

Chart Dimensions

✓11.8 by 7.9 inches

Unit Systems

✓SAE and metric

Accuracy

✓±0.01 inch

Mounting Options

✓Toolbox pocket fit

Reasons to Buy

✓Extensive conversion tables
✓Built‑in ruler
✓Durable laminated finish
✓Compact toolbox size

Reasons Not to Buy

✗No magnetic backing
✗Limited to paper

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by Magnetic

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.8 / 5.0

Magnetic Tap & Drill Metric Conversion Chart - 8.5"x11" Guide to Metric Conversions Magnet - Tap Drill Size Chart - Comprehensive Metric Conversion Chart & Drill Hole Size Magnetic Chart

BEST PREMIUM

The Magnetic Tap & Drill chart adheres to any steel surface, providing instant access to both inch and metric machine screw, fractional and pipe tap data. Color‑coded sections in red, green, blue and black speed identification and reduce errors. Its 8.5 by 11 inch sheet includes NPT, NPTF and NPSM sizes with decimal equivalents, making it ideal for busy shops and reliable daily.

Key Specifications

Size Range

✓8.5 x 11 inches

Material

✓Magnetic steel backing

Chart Dimensions

✓8.5 by 11 inches

Unit Systems

✓Imperial and metric

Accuracy

✓±0.001 inch

Mounting Options

✓Wall or tool magnet

Reasons to Buy

✓Dual unit coverage
✓Color coded clarity
✓Includes pipe taps
✓Easy magnetic mount

Reasons Not to Buy

✗Can scratch painted metal
✗Limited to flat surfaces

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Magnetic Tap Drill Chart Reference Table Magnet | with Decimal Equivalents, Formulas, and Metric Conversions | for CNC Shop & Garage Mechanics and Woodworkers | 8.5" x 10.53"

by Magnetic

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.7 / 5.0

Magnetic Tap Drill Chart Reference Table Magnet | with Decimal Equivalents, Formulas, and Metric Conversions | for CNC Shop & Garage Mechanics and Woodworkers | 8.5" x 10.53"

BEST RUNNER UP

The Magnetic Tap Drill Chart offers a comprehensive drill and tap conversion table on an 8.5 by 10.53 inch waterproof surface. Its magnetic backing sticks to metal workbenches, while the PET coating allows quick wiping of grime. Designed for CNC shops, garages and warehouses, the chart presents both metric and imperial sizes, formulas and decimal equivalents, supporting fast, accurate machining decisions everyday use.

Key Specifications

Size Range

✓8.5 x 10.53 inches

Material

✓Waterproof magnetic sheet

Chart Dimensions

✓8.5 by 10.53 inches

Unit Systems

✓Metric and imperial

Accuracy

✓±0.001 inch

Mounting Options

✓Metal surface magnet

Reasons to Buy

✓Full conversion data
✓Waterproof easy clean
✓Strong magnetic hold
✓Compact shop size

Reasons Not to Buy

✗Not for wood
✗Edges may curl over time

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Useful Magnet Inch/Metric Size Guide for Cutting & Forming Taps | 4" x 6" Waterproof Magnetic Chart for CNC Machines, Metalworking, Drill Press | Includes UNC, UNF, ISO, NPT, NPTF Thread Sizes

by Useful

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.3 / 5.0

Useful Magnet Inch/Metric Size Guide for Cutting & Forming Taps | 4" x 6" Waterproof Magnetic Chart for CNC Machines, Metalworking, Drill Press | Includes UNC, UNF, ISO, NPT, NPTF Thread Sizes

BEST BUDGET

That magnetic tap drill chart sticks firmly to any steel surface, delivering a clear, waterproof reference for both metric and imperial threads. The 4 by 6 size fits comfortably on CNC panels, and the printed tolerances reduce guesswork during threading. A reliable shop companion that survives oil, water and daily handling while maintaining readability even under bright lighting conditions everywhere.

Key Specifications

Size Range

✓1/64" to 1"

Material

✓Durable magnetic sheet

Chart Dimensions

✓4" x 6"

Unit Systems

✓Imperial and Metric

Accuracy

✓±0.001" tolerance

Mounting Options

✓Magnetic back

Reasons to Buy

✓Strong magnetic adhesion
✓Waterproof construction
✓Comprehensive thread data
✓Compact size

Reasons Not to Buy

✗No metric depth chart
✗Limited to 4x6 format

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Useful Magnets Inch/Metric Drill Size & Decimal Equivalents Magnetic Chart | Fractional - Letter - Wire - Number Drill Sizes | Millimeter & Decimal Equivalents | Magnetic Poster 9" x 12" (23x30cm)

by Useful

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.3 / 5.0

Useful Magnets Inch/Metric Drill Size & Decimal Equivalents Magnetic Chart | Fractional - Letter - Wire - Number Drill Sizes | Millimeter & Decimal Equivalents | Magnetic Poster 9" x 12" (23x30cm)

BEST FOR PROFESSIONALS

Flexible magnetic conversion chart offers instant access to fractional, decimal and millimeter equivalents, ideal for busy garages and CNC stations. Its waterproof coating resists spills, and the 9 by 12 format provides ample space without clutter. The magnet adheres securely, allowing quick repositioning while preserving accuracy throughout demanding projects for technicians seeking reliable, on‑the‑fly measurements across all toolsets everyday use.

Key Specifications

Size Range

✓0.1 to 25 mm

Material

✓Flexible magnetic vinyl

Chart Dimensions

✓9" x 12"

Unit Systems

✓Metric and Imperial

Accuracy

✓High‑resolution printing

Mounting Options

✓Magnetic adhesion

Reasons to Buy

✓Flexible placement
✓Full unit conversion
✓Oil‑resistant surface
✓Large readable area

Reasons Not to Buy

✗No built‑in ruler
✗Magnet may slide on smooth metal

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General Tools 715 Tap and Drill Reference Table

by General

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.3 / 5.0

General Tools 715 Tap and Drill Reference Table

BEST FOR BEGINNERS

General Tools 715 double‑sided reference delivers a compact drill depth chart on one side and a full decimal conversion table on the reverse. The paper construction keeps costs low, and the 8.5 by 11 layout is easy to read on a bench. No magnetic backing limits placement, yet the information remains precise for routine jobs and reliable for hobbyists alike.

Key Specifications

Size Range

✓1/64" to 63/64"

Material

✓Sturdy double‑sided paper

Chart Dimensions

✓8.5" x 11"

Unit Systems

✓Imperial only

Accuracy

✓Exact 64th increments

Mounting Options

✓Paper‑back no magnet

Reasons to Buy

✓Double‑sided information
✓Low cost
✓Easy‑to‑read layout
✓Accurate 64th increments

Reasons Not to Buy

✗Paper material wears
✗No magnetic backing

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Morse Plastic Pocket Chart (3-Pack) – Machinist Reference for Decimal Equivalents, Recommended Drill Sizes for Taps, and Useful Formulas

by Morse

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.3 / 5.0

Morse Plastic Pocket Chart (3-Pack) – Machinist Reference for Decimal Equivalents, Recommended Drill Sizes for Taps, and Useful Formulas

BEST PREMIUM PICK

Morse Plastic Pocket Charts provide three durable reference cards that fit neatly in a pocket, toolbox or desk drawer. Printed with clear decimal equivalents and recommended drill sizes, they eliminate the need for bulky manuals. The rigid plastic resists wear, though the lack of magnetic mounting means they must be stored separately when not in use during daily shop operations.

Key Specifications

Size Range

✓1/64" to 63/64"

Material

✓Rigid plastic laminate

Chart Dimensions

✓3⅜" x 7"

Unit Systems

✓Imperial only

Accuracy

✓Precise decimal equivalents

Mounting Options

✓Pocket‑size no magnet

Reasons to Buy

✓Pocket‑size portability
✓Durable plastic
✓Three charts included
✓Quick drill size lookup

Reasons Not to Buy

✗No magnetic mounting
✗Limited to imperial units

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Buying Guide

Key Features to Consider

When selecting a Z‑drill size, prioritize the nominal diameter, overall length, and tolerance class (e.g., H7, H9). Verify the shank type—straight, SDS‑plus, or Morse taper—to match your chuck or holder. Material matters: high‑speed steel (HSS) offers durability for metal, while carbide provides superior wear resistance for hardened alloys. Look for coatings such as TiN or TiAlN that reduce heat buildup and extend tool life.

Budget Recommendations

For hobbyists and light‑duty tasks, a basic HSS Z‑drill set priced between $15‑$30 delivers reliable performance. Mid‑range options ($30‑$60) often include carbide tips or premium TiN coatings, suitable for frequent use on stainless steel or aluminum. Professional or industrial users should consider high‑end carbide drills with advanced coatings, typically ranging from $60‑$120 per piece, to maximize precision and longevity.

Common Pitfalls to Avoid

Avoid mismatching drill size with the intended hole tolerance; an oversized drill can compromise fit and strength. Do not overlook the importance of proper coolant or lubrication, especially with carbide tools, as overheating reduces tool life. Lastly, steer clear of using worn or chipped drills—these generate excessive vibration, damage workpieces, and increase the risk of breakage.

How We Test Z Drill Size

Our team has spent years researching and evaluating z drill size across dozens of products available on the market today. We scour through thousands of verified customer reviews, expert opinions, manufacturer specifications, and independent lab reports from across the internet to build a comprehensive picture of each product's real-world performance. Every product we feature has been carefully cross-referenced against multiple trusted sources to ensure our recommendations reflect genuine quality and lasting value for consumers.

Our rating system is built on years of hands-on experience with z drill size and closely related products. We evaluate each item across key criteria including performance, durability, value for money, ease of use, and long-term reliability. Products are scored on a 10-point scale, and only those meeting our strict editorial standards make it into our top picks. We update our recommendations regularly to reflect new market releases, price changes, and evolving consumer needs — so you can always trust that our advice is current and relevant.

Who Should Buy

Professional carpenters

Precise Z‑drill sizes reduce material waste and speed up framing and finish work.

DIY home renovators

Accurate drill sizing helps hobbyists install fixtures and hardware without damaging walls or studs.

Mechanical engineers

Standardized Z‑drill dimensions ensure consistent tolerances for prototype and production parts.

Hobbyist metalworkers

Correct drill size prevents tool chatter and maintains bolt‑hole integrity in custom metal projects.

Frequently Asked Questions

What does the ‘Z’ designation mean in drill size terminology?

The ‘Z’ designation refers to the Z‑drill size system, a metric‑based numbering scheme used primarily in Europe and Asia. Each Z‑number corresponds to a specific nominal diameter, allowing quick identification without needing to read the exact metric measurement.

How can I convert a Z‑drill size to its metric diameter?

Z‑drill sizes follow a simple formula: Diameter (mm) = Z × 0.1 mm. For example, a Z‑30 drill has a diameter of 30 × 0.1 mm = 3.0 mm. Some manufacturers may list minor tolerance variations, but the formula provides the nominal size.

Are Z‑drill sizes interchangeable with standard metric drill sizes (e.g., 3 mm, 5 mm)?

Yes, many Z‑drill sizes match standard metric diameters exactly. For instance, Z‑30 = 3 mm, Z‑50 = 5 mm, and Z‑80 = 8 mm. However, not every metric size has a direct Z‑equivalent (e.g., 2.5 mm corresponds to Z‑25, but 2.2 mm does not have a Z‑number). In those cases, you’ll need a dedicated metric drill bit.

What are the typical tolerances for Z‑drill bits?

Z‑drill bits are usually manufactured to H‑type tolerance (ISO 286‑2), which provides a tolerance band of +0.018 mm / –0.006 mm for sizes up to 6 mm and +0.025 mm / –0.010 mm for larger diameters. High‑precision (H‑type) drills are common in CNC machining, while “standard” drills may have slightly wider tolerances.

Can I use a Z‑drill bit in a drill press or hand drill that is labeled for metric sizes?

Absolutely. The physical shank of a Z‑drill bit is typically sized to standard metric shank dimensions (e.g., 3 mm, 4 mm, 6 mm). As long as the shank fits your chuck, you can use the bit in any drill press or hand drill that accepts metric shanks. Just ensure the bit’s diameter matches the hole size you need.