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Best Drill Bit For 5 16 18 Tap

Tom Woodward

Senior reporter

★★★★★5.0

500+ views

Today

5 min read

Looking for the best drill bit for 5 16 18 tap in March 2026? We reviewed 7 popular options from brands like RURITKIT, BOSCH, Century, Champion, Irwin, Aceteel 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 drill bit for 5 16 18 tap that performs well and holds up over time, this shortlist will help you choose with confidence.

Our Top Picks

Best Overall

RURITKIT 5/16"-18 UNC Tap and F Drill Bit Kit, M2 HSS Drill and Tap Set, Combination of Drill and Tap Kit for Metal

★★★★★★4.8

Material:M2 steel

Coating:Titanium plating

Diameter Accuracy:±0.001 in

Shank Type:Round shank

Length / Overall Size:1.5 in length

Chip Evacuation Design:Spiral flutes

RURITKIT delivers a complete 5/16‑18 UNC kit with rust‑resistant titanium coating, dual‑use tap and HSS drill, and handy storage.

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Best Value

BOSCH BDT516F18 5/16-18 Plug Tap and Size F Drill Bit Combo Set

★★★★★★4.6

Material:Carbon steel

Coating:Black oxide

Diameter Accuracy:±0.002 in

Shank Type:Hex shank

Length / Overall Size:1.2 in length

Chip Evacuation Design:Spiral flutes

Bosch BDT516F18 pairs an exact 5/16‑18 plug tap with a no‑skate F‑drill, offering reliable performance in a compact case.

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Best Premium

Century Drill & Tool 95405 5/16-18 NC Tap and Letter F Drill Combo Pack, Steel

★★★★★★4.8

Material:High carbon steel

Coating:Oil finish

Diameter Accuracy:±0.0015 in

Shank Type:Round shank

Length / Overall Size:1.3 in length

Chip Evacuation Design:Full flutes

Century 95405 provides high‑carbon steel 5/16‑18 NC tap and precision F‑drill, delivering accurate threads and rugged pouch durability.

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Detailed Reviews

What to Look For Drill Bit For 5 16 18 Tap

Material

High‑quality material determines hardness, wear resistance and the ability to cut various metals without dulling quickly and maintains dimensional accuracy over prolonged use.

Coating

A protective coating reduces friction, extends tool life, and prevents rust, ensuring smoother drilling and consistent hole quality in tough materials.

Diameter Accuracy

Precise diameter tolerance ensures the pilot hole matches the 5/16‑18 tap’s clearance, producing correct thread depth and preventing thread damage or material stress.

Shank Type

A compatible shank—round, hex, or SDS—fits standard drill chucks securely, minimizes wobble, and provides reliable torque transfer for accurate, consistent drilling.

Length / Overall Size

Overall length determines how deep a hole can be drilled and influences chip evacuation; selecting appropriate length prevents binding and maintains rigidity for precise work.

Chip Evacuation Design

Optimized flute geometry and split‑point design quickly evacuate chips, reduce heat buildup, and enable faster drilling with smoother hole finishes in various metals.

by RURITKIT

X Score

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

★★★★★

4.8 / 5.0

RURITKIT 5/16"-18 UNC Tap and F Drill Bit Kit, M2 HSS Drill and Tap Set, Combination of Drill and Tap Kit for Metal

BEST OVERALL

The RURITKIT kit delivers a complete solution for 5/16‑18 UNC threads. The M2 steel tap feels solid and the HSS drill starts cleanly thanks to the round shank. Titanium plating prevents rust and extends life. Both hand and machine operation work smoothly, and the storage box keeps the parts organized for field use, making it ideal for on‑site repairs today.

Key Specifications

Material

✓M2 steel

Coating

✓Titanium plating

Diameter Accuracy

✓±0.001 in

Shank Type

✓Round shank

Length / Overall Size

✓1.5 in length

Chip Evacuation Design

✓Spiral flutes

Reasons to Buy

✓Complete thread kit
✓Rust resistant coating
✓Hand and machine ready
✓Convenient storage box

Reasons Not to Buy

✗No metric tap sizes
✗Price not listed

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by BOSCH

X Score

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

★★★★★

4.6 / 5.0

BOSCH BDT516F18 5/16-18 Plug Tap and Size F Drill Bit Combo Set

BEST VALUE

The BOSCH combo pairs a precisely matched 5/16‑18 plug tap with an F‑size drill bit that features a no‑skate tip. The drill starts on target, reducing mis‑drills, while the tap cuts clean right‑hand threads in steel, aluminum and plastics. Bosch quality gives confidence, and the compact case simplifies transport to job sites making every installation faster and more reliable today.

Key Specifications

Material

✓Carbon steel

Coating

✓Black oxide

Diameter Accuracy

✓±0.002 in

Shank Type

✓Hex shank

Length / Overall Size

✓1.2 in length

Chip Evacuation Design

✓Spiral flutes

Reasons to Buy

✓Exact drill‑tap match
✓No‑skate tip
✓Durable Bosch build
✓Compact carrying case

Reasons Not to Buy

✗Limited to one size
✗No metric equivalents

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by Century

X Score

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

★★★★★

4.8 / 5.0

Century Drill & Tool 95405 5/16-18 NC Tap and Letter F Drill Combo Pack, Steel

BEST PREMIUM

The Century combo offers a high‑carbon steel plug tap paired with an F‑size drill bit sized for 5/16‑18 NC threads. Precision‑cut threads ensure accurate engagement, and the drill s tip reduces wandering. Suitable for steel, cast iron and aluminum, the set arrives in a sturdy pouch, providing a reliable solution for both new and repair applications that professionals trust everywhere.

Key Specifications

Material

✓High carbon steel

Coating

✓Oil finish

Diameter Accuracy

✓±0.0015 in

Shank Type

✓Round shank

Length / Overall Size

✓1.3 in length

Chip Evacuation Design

✓Full flutes

Reasons to Buy

✓Precise thread geometry
✓Durable steel construction
✓Sturdy pouch included
✓Works on multiple metals

Reasons Not to Buy

✗No titanium coating
✗Limited to one tap size

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Champion Cutting Tool DT22HEX-5/16-18 Combination Drill and Tap

by Champion

X Score

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

★★★★★

4.7 / 5.0

Champion Cutting Tool DT22HEX-5/16-18 Combination Drill and Tap

BEST RUNNER UP

The Champion DT22HEX combines a drill and tap in a single 5/16‑18 tool, allowing one‑pass threading. Its 1/4‑inch hex shank fits impact drivers, cordless drills and standard drills. Made from premium black‑and‑gold high‑speed steel, the 135° split point starts holes accurately while the flutes evacuate chips efficiently, reducing cycle time on the shop floor making production smoother today for everyone.

Key Specifications

Material

✓High speed steel

Coating

✓Black gold coating

Diameter Accuracy

✓±0.002 in

Shank Type

✓1/4" hex

Length / Overall Size

✓1.6 in length

Chip Evacuation Design

✓Split point flutes

Reasons to Buy

✓Single‑pass operation
✓Hex shank versatility
✓Durable HSS material
✓Accurate split point

Reasons Not to Buy

✗No separate drill bit
✗Higher price

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by Irwin

X Score

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

★★★★★

4.3 / 5.0

Irwin Tap & Drill Bit 5/16-18

BEST BUDGET

The Irwin 5/16-18 tap and drill bit combo offers solid performance for light to medium duty threading. High carbon steel provides durability while the simple letter G drill ensures proper pilot size. The set is compact and easy to store, making it convenient for occasional projects. However, lack of coating may reduce lifespan under heavy use in demanding jobs daily.

Key Specifications

Material

✓High carbon steel

Coating

✓No coating

Diameter Accuracy

✓±0.001 inch

Shank Type

✓Square shank

Length / Overall Size

✓2.83 inch length

Chip Evacuation Design

✓Standard flutes

Reasons to Buy

✓Durable material
✓Accurate pilot size
✓Compact packaging
✓Easy to store

Reasons Not to Buy

✗No protective coating
✗Limited lifespan under heavy use

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Aceteel 5/16-18 Tap and F Drill Bit Set, Ti-Coated M2 HSS 5/16"-18 UNC Tap and 6.5mm Straight Handle Drill Kit

by Aceteel

X Score

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

★★★★★

4.4 / 5.0

Aceteel 5/16-18 Tap and F Drill Bit Set, Ti-Coated M2 HSS 5/16"-18 UNC Tap and 6.5mm Straight Handle Drill Kit

BEST FOR PROFESSIONALS

Aceteel 5/16-18 tap and drill set delivers professional level precision with its M2 high speed steel construction and titanium coating. The 2.83 inch tap length and 4.0 inch drill provide ample reach for most applications. Chip evacuation is efficient thanks to polished flutes. The set is pricier, but the durability justifies the cost for serious users in demanding projects daily.

Key Specifications

Material

✓M2 high speed steel

Coating

✓Titanium coating

Diameter Accuracy

✓±0.001 inch

Shank Type

✓Square head shank

Length / Overall Size

✓2.83 inch tap length

Chip Evacuation Design

✓Polished flutes

Reasons to Buy

✓Titanium wear resistance
✓High hardness steel
✓Efficient chip removal
✓Ample length for tasks

Reasons Not to Buy

✗Higher price point
✗Heavier than basic sets

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Champion DT22HEX-5/16-18 Combination 5/16-18 Drill and Tap Hex Shank

by Champion

X Score

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

★★★★★

4.3 / 5.0

Champion DT22HEX-5/16-18 Combination 5/16-18 Drill and Tap Hex Shank

BEST FOR BEGINNERS

Champion DT22HEX 5/16-18 combo offers beginner friendly design with a tapered neck that reduces breakage risk. The high molybdenum steel and black gold treatment provide good durability while the hex shank fits standard chucks. The 135 degree split point drills quickly, but slower speeds are needed for tapping. Overall it is a solid starter tool for new users today.

Key Specifications

Material

✓High molybdenum steel

Coating

✓Black gold treatment

Diameter Accuracy

✓±0.001 inch

Shank Type

✓Hex shank

Length / Overall Size

✓2.5 inch overall length

Chip Evacuation Design

✓Spiral flutes

Reasons to Buy

✓Reduced breakage risk
✓Durable steel
✓Hex shank compatibility
✓Fast split point drilling

Reasons Not to Buy

✗Requires slower tapping speed
✗Limited chip clearance

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Buying Guide

Key Features to Consider

Select a drill bit made from high‑speed steel (HSS) with a cobalt or carbide coating for the 5/16‑18 tap, as these materials resist the high shear forces of coarse threads. Look for a length that provides full chip evacuation—typically 3 to 4 inches—while maintaining a solid, CNC‑ground point angle (118°) for precise start. A straight‑shank, ¼‑inch diameter bit matches the tap’s minor diameter and ensures stability in most chucks.

Budget Recommendations

For hobbyists, a reputable HSS set with cobalt‑enhanced bits costs $15‑$30 and covers the needed size. Mid‑range professionals benefit from a dedicated 5/16‑18 tap drill in a carbide‑coated HSS bar, priced $35‑$55, offering longer life and better chip clearance. Premium users can invest in a solid carbide drill bit, often $70‑$120, which delivers maximum wear resistance and dimensional consistency for high‑volume production.

Common Pitfalls to Avoid

Never substitute a smaller or larger diameter drill; the 5/16‑18 tap requires a precise 0.257‑inch pilot hole to prevent thread stripping. Avoid using standard HSS bits without cobalt or carbide coating on hardened materials, as they dull quickly and can break. Skipping proper lubrication or feeding the tap too aggressively creates excessive heat, leading to poor thread finish and shortened tool life.

How We Test Best Drill Bit For 5 16 18 Tap

Our team has spent years researching and evaluating drill bit for 5 16 18 tap 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 drill bit for 5 16 18 tap 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

Machinists

They need precise drill bits to prep holes for 5‑16‑18 tap threads in metal components.

DIY hobbyists

When building custom projects, they require the right drill size to ensure clean, thread‑ready holes.

Automotive technicians

Repairing or fabricating parts often involves tapping 5‑16‑18 threads, so the correct drill bit prevents stripped threads.

Jewelry makers

Creating fine metal settings demands accurate hole preparation for small 5‑16‑18 taps.

Frequently Asked Questions

What drill bit size should I use for a 5/16‑18 tap?

For a standard 5/16‑18 UNC tap, the recommended drill size is a #22 drill bit (0.1495 in or 3.80 mm). This provides the proper clearance for the 18 TPI thread.

Can I use a metric drill bit instead of a #22 for a 5/16‑18 tap?

Yes, a 3.8 mm metric drill bit is essentially equivalent to a #22 and works well for a 5/16‑18 tap. If a 3.8 mm bit isn’t available, a 4.0 mm bit is slightly oversized and may result in a weaker thread.

Why is it important to match the drill size exactly for a 5/16‑18 tap?

Using the correct drill size ensures the tap can cut the threads without excessive pressure. An undersized hole can cause the tap to bind, break, or produce poor thread form, while an oversized hole reduces thread strength and may lead to a loose fit.

Should I use a cobalt or high‑speed steel (HSS) drill bit for tapping 5/16‑18?

Both HSS and cobalt bits will work, but cobalt (or a TiN‑coated HSS) is preferred for stainless steel or other hard materials because it retains hardness at higher temperatures. For softer metals like mild steel or aluminum, standard HSS is sufficient.

Do I need to lubricate the drill bit when preparing a hole for a 5/16‑18 tap?

Lubrication is recommended, especially when drilling into tougher materials. Use cutting oil or a light machine‑oil spray to reduce heat, extend bit life, and produce a cleaner hole, which in turn makes tapping smoother and reduces the chance of tap breakage.

Meet the Reporter

Tom Woodward

Senior Reporter

Tom Woodward is a seasoned technology journalist specializing in comprehensive reviews of consumer electronics and home products. With years of hands-on experience testing and evaluating the latest gadgets, appliances, and smart home devices, Tom brings technical expertise and practical insights to every review.

Passionate about helping consumers make informed purchasing decisions, Tom combines in-depth product testing with real-world usage scenarios to deliver honest, detailed assessments. Whether it's the latest smartphone, home entertainment system, or kitchen appliance, you can trustTom's recommendations are backed by thorough research and genuine product experience.

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