Drill Conversion Chart Pdf

DRILL SIZE CHART - printable PDF. This drill size chart is used to convert hole sizes to decimal inch equivalent or millimeters. The drill size chart can be used for any drill machine and this chart would be used near the drill or milling machine.

Is Manual Machining Faster than CNC for Simple Parts?

If you just want a simple tap drill chart in Metric and Imperial sizes, or a pdf you can print and post in your workshop, scroll on down.

But, before you do, wouldn’t you like to hear about something that’s much better in every way? Something that’ll make it much less likely you’ll break a tap? Something a little more modern than a simple chart?

Let us help, and BTW, it’s completely free too!

Number Drill Conversion Chart

What’s better than a drill bit size chart?

Make no mistake: having a good drill bit size chart (sometimes called a “drill index”) is a very handy thing indeed to have around. If it has information on which twist drill size to use for tapping, so much the better. But in this age of computers and the Internet, you can do better.

Newsflash: There Isn’t Just One Drill Bit Size for a Tap

Let’s start with an important fact–there isn’t just one drill bit size to use for a given tap size. There are several. Moreover, the size recommended in most drill bit size charts is very often not the best size to use. The same is true of the size recommended on the tap and even the recommended size from the tap manufacturer. Anytime you see just one size being recommended, you know you can do better–one size does not fit all when it comes to tapping. How can that be? Well, it’s actually pretty simple. To know which drill bit size is right for your particular tapping application, you need to consider what thread percentage you want when you’re done tapping.

Pdf

What’s Thread Percentage and Why Care?

Imagine the fully formed internal thread. Each thread rises from valley to peak. Now suppose you ran a twist drill down the hole and shaved off some of the peaks. They’re pretty delicate anyway and will wear off quickly. In fact, they contribute surprisingly little strength. Kennametal says a 100% thread is only 5% stronger than 75% thread. But here is the real kicker: That 100% thread requires 3 times the power to tap! Why do you care? because it is the power to tap that breaks taps, for one thing. Getting 95% of the strength with 1/3 the force on the tap means you’re dramatically less likely to break the tap off in the hole. Now we all know what happens when we break a tap, right? Sailors would go running out of the shop if they heard the language we use in that case. It’s just not a happy thing. But is it okay to have less than 100% threads? In fact, many standards bodies insist on it. For example, American National and Unified thread specifications provide for a maximum of 83 1/3% thread. These specifications also provide a minimum value that varies from approximately 53% to 75%, depending upon the diameter and pitch of thread.

Thread Percentage and Tap Drill Charts

Most tap drill charts call out only one tap drill size, and that will produce an approximate 75 percent thread. For most applications, you can get longer tap tool life and lower likelihood of breaking a tap off in the hole by using a lower percent of thread. Companies like Guhring actually recommend 60% to 70% percentage of thread for most applications because it significantly lowers the torque force required to tap without giving up much thread strength. That’s why these lower percentage are a better idea for your tap’s tool life!

Thread Percentage vs Strength Chart

Let’s take a closer look at the relationship between torque and thread strength based on thread percentage:

Redmarks the typical 75% percent of thread drill recommendation. Chart courtesy of Tapmatic.

Red marks the typical 75% percent of thread drill recommendation. What stands out is the relationship between the torque required to tap (solid black line) and the strength of the tapped hole (dashed line). When We accept the 75% percent of thread the average drill chart hands us, we’re subjecting our poor taps to a huge amount of additional torque for very little extra strength!

Is it any wonder the darn taps give up and break on us after that kind of abuse?

So what’s the right way to choose a thread percentage and how do we get from there to a proper drill size?

General Guidelines for Choosing Thread Percentage

Try this approach, which is based on material and type of work:

The material matters because we can afford higher thread engagement in softer materials and we actually need it to increase thread strength. For hard or tough materials, a lower percentage can really help tap life and those materials have lots of strength even at the lower percentages. In deeper holes, we run the most risk of breaking a tap and in sheet metal we need the strongest threads because there is much thread depth for holding power.

Tapping Drill Size Problem #2: Form Taps vs Cut Taps

Just one more little wrinkle is that Form Taps (also called “Roll Taps” because they perform thread rolling rather than thread cutting) need a different sized hole than Cut Taps, and most drill size charts only show drill sizes for Cut Taps. As a machinist, you’re no doubt aware of the many advantages Form Taps have over Cut Taps:

  1. Form Taps don’t make any chips. This is a huge advantage when threading deep holes and especially for blind holes where chips can jam up in the bottom of the hole.
  2. Form Taps make stronger threads than Cut Taps. What could be better?
  3. Better Thread Gaging. Form taps work by cold forming the metal in the hole. Since no chips are made, the likelihood of producing oversized threads is far less than for Cut Taps.
  4. Stronger Taps. It just gets better and better-form taps are stronger and less likely to break than cut taps.
  5. Longer Tap Life. Form taps, properly used, can last 3 to 20 times longer than cutting taps because they have no cutting edge to dull.
  6. Faster Tapping. You can run higher spindle speeds with form taps than cut taps.

In fact, the main disadvantage of Form Taps is they can’t be used on materials that are too hard. The hardness limit for Form Taps is higher than you probably think (they’re good for much more than aluminum), but there is a limit nonetheless. Given all that, you’re definitely going to need to figure out Form Tap Drill Sizes too!

Quick Tip: If you’re wondering about the different types of thread taps, click the link for our complete guide.

How Do I Go From Thread Percentages to Tap Drill Size?

Well, you can’t use a standard drill chart, that much is clear. You could calculate the optimal size for a particular percentage of thread and then go to a standard drill chart to find the nearest size. That works, but it is a fair amount of trouble.

I promised you a better way, and here it is–you can use our G-Wizard Calculator’s Thread Database to tell you exactly what you need to know, and it is very fast and easy to do so. Let’s walk through it:

  1. Go to the Thread Database in G-Wizard by selecting the Threads tab.
  2. Choose which thread you want. G-Wizard has a bunch of them in its database.
  3. In the lower left corner is a convenient table of tap drill sizes with a column showing thread percentage. You can even select Form or Cut Taps to change the drill sizes.

Here’s what it looks like:

Tapping Drill Chart for 1/4-20 Thread

Nice, huh? It saves people a lot of time. There’s a whole ton of other very handy reference time savers there too, not to mention the world’s best Feeds and Speeds Calculator. I’ve all but quit having to dig through my Machinery’s Handbook to find information–I just use G-Wizard.

Here’s something else–you can get lifetime access to all the reference calculators and materials except the Feeds and Speeds Calculator just by signing up for a Free Trial of G-Wizard. That’s right, it is completely free to access all that just by signing up for a free trial and you’ll also get all the upgrades and customer service for life! Plus, buy the $79 version and you get up to 1 HP on the Feeds and Speeds too for life.

So what’s the catch? Why does anyone ever pay more than $79?

Many hobbyists don’t pay more than $79, BTW. The catch is a spindle power limit. When you buy the 1 year G-Wizard for $79, you get 1 year of unlimited spindle power for Feeds and Speeds. When that expires, you get a spindle power limit of 1 HP. That limit is based on however many years you subscribe for. You can increase it any time you like by renewing the subscription. Or, if you don’t like subscriptions, you can also by the product outright. And we never charge for updates or customer service.

So go ahead, give G-Wizard free trial, a try. You’ll be surprised at all the time it saves you on things like Tap Drill Sizes, not to mention the longer tool life, better surface finish, and shorter cycle times you’ll get from better Feeds and Speeds.

Bonus: Depth Clearance When Tapping Blind Holes

Blind Holes are particularly prone to breaking taps. It’s harder to clear the chips for one thing, but the other thing is machinists don’t leave enough clearance at the bottom of the hole.

Most don’t even know how much clearance they should be leaving. But, G-Wizard will calculate the clearance for you. Just one more way it’s saving you time and trouble.

Hey, What About that Free Drill Bit Size Chart?

Here you go, Metric and Imperial sizes are called out in the “Use” column in the chart below. It’s even an NPT Tap Drill Chart:

InchMetric (mm)DesignationUse
0.01350.3429#80
0.01450.3683#79
0.01560.39691/64″#0 Pilot, Soft-Wood
0.01600.4064#78
0.01800.4572#77
0.01970.5.5 mm
0.02000.508#76
0.02100.5334#75
0.02250.5715#74
0.02400.6096#73
0.02500.635#72
0.02600.6604#71
0.02800.7112#70
0.02920.74168#69
0.02950.75.75 mmM1x.25 tap drill size
0.03100.7874#68
0.03130.79381/32″#0 Pilot, Hard-Wood #1 Pilot, Hard & Soft-Wood #2 Pilot, Soft-Wood
0.03200.8128#67
0.03300.8382#66
0.03350.85.85 mmM1.1x.25 coarse tap drill size
0.03500.889#65
0.03600.9144#64
0.03700.9398#63
0.03740.95.95 mmM1.2x.25 coarse tap drill size
0.03800.9652#62
0.03900.9906#61
0.039411 mm
0.04001.016#60
0.04101.0414#59
0.04201.0668#58
0.04301.0922#57
0.04331.11.1 mmM1.4x.3 coarse tap drill size
0.04651.1811#56
0.04691.19063/64″#0-80 UNF tap drill size #2 Pilot, Hard-wood, #3 Pilot, Soft-Wood #4 Pilot, Soft-Wood
0.04921.251.25 mmM1.6x.35 coarse tap drill size
0.05121.31.3 mmM1.7x.35 coarse tap drill size
0.05201.3208#55
0.05501.397#54
0.05711.451.45 mmM1.8x.35 coarse tap drill size
0.05911.51.5 mm
0.05951.5113#53#1-64 UNC, #1-72 UNF tap drill size
0.06251.58751/16″#0 Wood Shank Hole, #3 Pilot, Hard-Wood, #4 Pilot, Hard-wood #5 Pilot, Soft-wood, #6 Pilot, Soft-wood, #7 Pilot, Soft-wood
0.06301.61.6 mmM2x.4 coarse tap drill size
0.06351.6129#52
0.06701.7018#51
0.06891.751.75 mmM2.2x.45 coarse coarse tap drill size
0.07001.778#50#2-64 UNF, #2-56 UNC tap drill size
0.07301.8542#49
0.07601.9304#48
0.07811.98445/64″#1 Wood Shank Hole#5 Pilot, Hard-wood, #6 Pilot, Hard-wood #8 Pilot, Soft-wood, #9 Pilot, Soft-wood
0.07851.9939#47#3-48 UNC tap drill size
0.078722 mm
0.08072.052.05 mmM2.5x.45 coarse tap drill size
0.08102.0574#46
0.08202.0828#45#3-56 UNF tap drill size
0.08602.1844#44
0.08902.2606#43#4-40 UNC tap drill size
0.09352.3749#42#4-48 UNF tap drill size
0.09382.38133/32″#2 Wood Shank Hole, #7 Pilot, Hard-wood, #8 Pilot, Hard-wood, #10 Pilot, Soft-wood, #11 Pilot, Soft-wood
0.09602.4384#41
0.09802.4892#40
0.09842.5M3x.5 coarse tap drill size
0.09952.5273#39
0.10152.5781#38#5-40 UNC tap drill size
0.10402.6416#37#5-44 UNF tap drill size
0.10652.7051#36#6-32 UNC tap drill size
0.10942.77817/64″#3 Wood Shank Hole, #4 Wood Shank Hole, #9 Pilot, Hard-wood #10 Pilot, Hard-wood, #12 Pilot, Soft-wood, #14 Pilot, Soft-wood
0.11002.794#35
0.11102.8194#34
0.11302.8702#33#6-40 UNF tap drill size
0.11422.9M3.5x.6 coarse tap drill size
0.11602.9464#32
0.118133 mm
0.12003.048#31
0.12503.1751/8″#5 Wood Shank Hole, #11 Pilot, Hard-wood, #12 Pilot, Hard-wood
0.12853.2639#30
0.12993.33.3 mmM4x.7 coarse tap drill size
0.13603.4544#29#8-32 UNC, #8-36 UNF tap drill size
0.13783.53.5 mmM4x.5 Fine tap drill size
0.14053.5687#28
0.14063.57199/64″#6 Wood Shank Hole, #14 Pilot, Hard-wood, #16 Pilot, Soft-wood #18 Pilot, Soft-wood
0.14173.63.6 mmM4x.35 Fine tap drill size
0.14403.6576#27
0.14573.73.7 mmM4.5x.75 coarse tap drill size
0.14703.7338#26
0.14953.7973#25#10-24 UNC tap drill size
0.15203.8608#24
0.15403.9116#23
0.15633.96885/32″#7 Wood Shank Hole, #16 Pilot, Hard-wood
0.15703.9878#22
0.157544 mm
0.15904.0386#21#10-32 UNF tap drill size
0.16104.0894#20
0.16544.24.2 mmM5x.8 coarse tap drill size
0.16604.2164#19
0.16954.3053#18
0.17194.365611/64″#8 Wood Shank Hole, #20 Pilot, Soft-wood
0.17304.3942#17#12-24 UNC tap drill size
0.17704.4958#16
0.17724.54.5 mmM5x.5 Fine tap drill size
0.18004.572#15#12-28 UNF tap drill size
0.18204.6228#14
0.18504.699#13
0.18754.76253/16″#9 Wood Shank Hole, #10 Wood Shank Hole, #18 Pilot, Hardwood
0.18904.8006#12
0.19104.8514#11
0.19354.9149#10
0.19604.9784# 9
0.196955 mmM6x1 coarse tap drill size
0.19905.0546# 8
0.20105.1054# 71/4″-20 UNC tap drill size
0.20315.159413/64″#11 Wood Shank Hole, #20 Pilot, Hard-wood
0.20405.1816# 6
0.20555.2197# 5
0.20675.255.25 mmM6x.75 Fine tap drill size
0.20905.3086# 4
0.21305.4102# 31/4″-28 UNF tap drill size
0.21655.55.5 mmM6x.5 Fine tap drill size
0.21885.55637/32″#12 Wood Shank Hole
0.22105.6134# 2
0.22805.7912# 1
0.23405.9436A
0.23445.953115/64″
0.236266 mmM7x1 coarse tap drill size
0.23806.0452B
0.24206.1468C
0.24606.2484D1/16″-27 NPT tap drill size
0.24616.256.25 mmM7x.75 Fine tap drill size
0.25006.351/4″#14 Wood Shank Hole
0.25006.35E
0.25596.56.5 mm
0.25706.5278F5/16″-18 UNC tap drill size
0.26106.6294G
0.26566.746917/64″#16 Wood Shank Hole
0.26606.7564H
0.26776.86.8 mmM8x1.25 coarse tap drill size
0.27206.9088I5/16″-24 UNF tap drill size
0.275677 mmM8x.5 Fine tap drill size
0.27707.0358J
0.28107.1374K
0.28137.14389/32″
0.28547.257.25 mmM8x.75 Fine tap drill size
0.29007.366L
0.29507.493M
0.29537.57.5 mmM8x1 Fine tap drill size
0.29697.540619/64″#18 Wood Shank Hole
0.30207.6708N
0.30717.87.8 mmM9x1.25 coarse tap drill size
0.31257.93755/16″3/8″-16 UNC tap drill size
0.315088 mmM9x1 Fine tap drill size
0.31608.0264O
0.32308.2042P
0.32818.334421/64″#20 Wood Shank Hole
0.33208.4328Q3/8″-24 UNF tap drill size
0.33468.58.5 mmM10x1.5 coarse tap drill size
0.33908.6106R1/8″-27 NPT tap drill size
0.34388.731311/32″
0.34658.88.8 mmM10x1.25 Fine tap drill size
0.34808.8392S
0.354399 mmM10x1 Fine tap drill size
0.35809.0932T7/16″-14 UNC tap drill size
0.35949.128123/64″
0.36429.259.25 mmM10x.75 Fine tap drill size
0.36809.3472U
0.37409.59.5 mmM11x1.5 coarse tap drill size
0.37509.5253/8″
0.37709.5758V
0.38609.8044W
0.39069.921925/64″7/16″-20 UNF tap drill size
0.39371010 mmM11x1 Fine tap drill size
0.397010.0838X
0.401610.210.2 mmM12x1.75 coarse tap drill size
0.404010.2616Y
0.406310.318813/32″
0.413010.4902Z
0.413410.510.5 mmM12x1.5 Fine tap drill size
0.421910.715627/64″1/2″-13 UNC tap drill size
0.43311111 mmM12x1 Fine tap drill size
0.437511.11257/16″1/4″-18 NPT tap drill size
0.442911.2511.25 mmM12x.75 Fine tap drill size
0.452811.511.5 mm
0.453111.509429/64″1/2″-20 UNF tap drill size
0.468811.906315/32″
0.47241212 mmM14x2 coarse tap drill size
0.484412.303131/64″9/16″-12 UNC tap drill size
0.492112.512.5 mmM14x1.5 Fine tap drill size
0.500012.71/2″
0.503912.812.8 mmM14x1.25 Fine tap drill size
0.51181313 mmM14x1 Fine tap drill size
0.515613.096933/64″9/16″-18 UNF tap drill size
0.531313.493817/32″5/8″-11 UNC tap drill size
0.531513.513.5 mm
0.546913.890635/64″
0.55121414 mmM16x2 coarse tap drill size
0.562514.28759/16″5/8″-18 UNF tap drill size
0.570914.514.5 mmM16x1.5 Fine tap drill size
0.578114.684437/64″3/8″-18 NPT tap drill size
0.59061515 mmM16x1 Fine tap drill size
0.593815.081319/32″
0.609415.478139/64″
0.610215.515.5 mmM18x2.5 coarse tap drill size
0.625015.8755/8″
0.62991616 mmM18x2 Fine tap drill size
0.640616.271941/64″3/4″-10 UNC tap drill size
0.649616.516.5 mm
0.656316.668821/32″
0.66931717 mmM18x1 Fine tap drill size
0.671917.065643/64″
0.687517.462511/16″3/4″-16 UNF tap drill size
0.689017.517.5 mmM20x2.5 coarse tap drill size
0.703117.859445/64″1/2″-14 NPT tap drill size
0.70871818 mmM20x2 Fine tap drill size
0.718818.256323/32″
0.728318.518.5 mmM20x1.5 Fine tap drill size
0.734418.653147/64″
0.74801919 mmM20x1 Fine tap drill size
0.750019.053/4″
0.765619.446949/64″7/8″-9 UNC tap drill size
0.767719.519.5 mmM22x2.5 coarse tap drill size
0.781319.843825/32″
0.78742020 mmM22x2 Fine tap drill size
0.796920.240651/64″
0.807120.520.5 mmM22x1.5 Fine tap drill size
0.812520.637513/16″7/8″-14 UNF tap drill size
0.82682121 mmM24x3 coarseM22x1 Fine tap drill size
0.828121.034453/64″
0.843821.431327/32″
0.846521.521.5 mm
0.859421.828155/64″
0.86612222 mmM24x2 Fine tap drill size
0.875022.2257/8″1″-8 UNC tap drill size
0.885822.522.5 mmM24x1.5 Fine tap drill size
0.890622.621957/64″
0.90552323 mm
0.906323.018829/32″1″-12 UNF tap drill size
0.921923.415659/64″3/4″-14 NPT tap drill size
0.925223.523.5 mm
0.937523.812515/16″
0.94492424 mmM27x3 coarse tap drill size
0.953124.209461/64″
0.964624.524.5 mmM26x1.5 Fine tap drill size
0.968824.606331/32″
0.98432525 mmM27x2 Fine tap drill size
0.984425.003163/64″1-1/8″-7 UNC tap drill size
1.000025.41″

How About a Drill Bit Size Chart with Metric Tap Drills in PDF?

So you can print it and hang it up on the wall, right? No problem, you can print the chart above. Just select it, go to your web browser’s Print command, and tell it to just print the selection. They all handle it and then you’ll have a chart suitable to hang up.

Pssst: G-Wizard Even Does the Drill Bit Size Chart Better!

Okay, here’s the crazy thing. I generated that Free Drill Bit Size Chart using the data that G-Wizard uses. It can present the same chart only better:

Drill Conversion Chart Pdf

G-Wizard’s Drill Bit Size Chart…

How is G-Wizard’s Drill Bit Size Chart better? Simple: it’s got all the same info, but it is easier to use. You can type in a diameter to search straight to it. You can select just End Mill sizes in Imperial or Metric. You can sort by clicking on the column headers. It’s pretty darned cool. And it’s there whenever you need to specify a size in the Feeds and Speeds Calculator or you can access it in a larger format in the Quick Refs tab under “Drill Chart.”

Enjoy!

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More articles you may like:

The Tap drill and Chart templates are quite useful in evaluating the exact size of the drill for the tap so that the job is completed and rejection is not meted out. Efficient documentation is the key to avoiding failure and achieving the objectives successfully. One has to make sure that the thread percentage information is also entered to determine the overall strength of the joint in an impeccable manner. spanish alphabet chart template is handy for all type of plumbing task that requires higher accuracy and precision.

Related:

Tap Drill Chart Excel

The Tap drill chart excel consists of two columns namely screw size and the tap drill. You need to find the information that would suit the size of the tap. Using the template, the accuracy of the work is guaranteed in an easy and hassle free manner. It is available in excel format to the users, therefore, they can conduct operations by downloading from the internet.

Metric Tap Drill Chart

The metric tap drill chart comprises of thread and the screw size across different columns. Predefined measurements are already given to the users for guidance so that they use the right equipment. Apart from the above-mentioned information, tap drill column is divided into sub-columns with headers about the material such as aluminum and steel.You may also see measurement charts.

Equivalent Tap Drill Chart

It is available in PDF format to the users and could be downloaded from the website. The template contains critical information about the drill size and their decimal equivalent rounded off to four places. All the measurements are given in mm for the understanding of the plumbing professional. It is bound to go a long way in providing desired results to the users.You may also see number charts.

Tap Drill Chart Pipe Thread

Tap Drill Chart Sample

Standard Tap Drill Chart

Tap Drill & Thread Height Chart

Drill And Tap Chart

Tap Drill Size Chart for Standard Threads

Imperial Tap Drill Chart

Uses of these Templates

Tap drill charts have gone a long way in becoming a part of the manual of many professionals. They can use them as references to get the job completed quickly and effectively. Even a slight mistake in precision can hamper the project. Therefore, use the template as a reference point to get the desired results without any problem.You may also see numerology charts.

When and who will use?

Prior to installation of the new tap in residence or office, the drilling template is used. It consists of accurate data pertaining to the screw size that would help to arrive at the desired result.

Plumbers can use the tap drill chart to carry out different types of projects . Since the information is given in detail, it is possible for the people to analyze the parameter and take correct steps to resolve the issue. Rather than buying just any other screw, one should check the template readings and select the equipment accordingly. Materials used for tapping fall into different categories right from close fit to free fit. They have to be repaired by using the data from the template.You may also see decimal to fraction charts

People can use template while shopping for the screw as it should have certain thread measurement. ISO metric thread headers are available under the template to help the plumbers with the tap drill size company organization chart that is listed in the columns. Corresponding to various measurements one can hone in on the best screw available to accomplish the task. People following the American standard thread design can read the relevant section of the document.

National Drill and Tap Chart

Metric System Tap and Drill Chart

Recommended Tap and Drill Chart

Carburetor Main Jet Drill Conversion Chart

Millimeter Sizes Tap and Drill Chart

Tormach Tap and Drill Chart

Benefits of these Templates

There are various benefits for the users as far as the tap drill template is concerned. Since accurate documentation is available one line, you can always verify the measure to ensure that it is correct. Plumbing projects get rejected because of the incorrect screw size compared to the tap size. Measurements related to close and free fit are given in great detail in the template. In order to perform the clearance, hole drill pays special attention to the decimal equivalent figure.You may also see thai alphabet charts

You can download varieties of templates from the internet according to the requirements and specifications. The size of the screw and information related to the thread is also maintained in great detail. They combine together to accomplish the task without errors and meet the demands of the customers.You may also see weight conversion charts

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Drill Bit Conversion Chart Number To Fraction

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