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The Bump Key Guide

Posted by Taylor Banks on June 20, 2012 (24 Comments)

Many visitors to ACE Hackware inquire about how to make a bump key. Of course we'd love to be able to sell you a  professional bump key set, but if you don't want to spend the money, making a bump key requires just a bit of knowledge, a few tools, some spare time and this bump key guide! 

If you haven't already, we would encourage you to first read our post, "How does a bump key work?" to give you a basic understanding of the function and use of a bump key.

Things You Need to Make a Bump Key

  • Blank keys for your specific lock
  • A depth and/or spacing guide for your lock manufacturer's keys, OR
  • A digital caliper to measure depth and spacing, plus a real cut key for your (or a similar) lock
  • A triangular or taper file or a key clipper
  • This bump key guide

From the manufacturer's depth and spacing guide (or from your own measurements using a cut key for the manufacturer's lock you aim to bump), you'll need to establish at least the following two measurements to make effective bump keys:

  • Key shoulder to first cut
  • Distance between key cut centers

How to Make a Bump Key

Using these values, you'll make your first cut using the first value (key shoulder to first cut), then each subsequent cut will be spaced at equal intervals using the second value (distance between centers). As a general rule, you cut to the indented line on the blank key. However, for greater accuracy and improved efficacy of your home-made bump key, you'll probably also want to determine the cut depth, which is a precise measurement from the bottom of a cut to the bottom of the key (this information should also be provided in your lock manufacturer's depth and spacing guide). If you don't have an accurate cut depth, you can generally cut to the indented line (never below!) and your key will probably work in most locks.

It is very important that you make sure that the valleys in your key do not go below the indented line on the key, and also that the angle of your cuts are shallow enough to allow smooth insertion and removal of your bump key from your target lock. If the valleys are too deep, your bump key will probably not work. If your valleys are too steep, you may damage the lock or you may not be able to remove the key from the lock once you've bumped it! Our professional bump keys are cut according to the manufacturer's specified cut depth with gradual valleys and gentle peaks. 

Finally, once you've created all of the necessary peaks and valleys in your new bump key, you'll want to file a small bit off the tip and shoulder of the key (generally <= 1/2mm will suffice).

Bump Key Videos

The instructions in this bump key guide will get you started, but if you want to know how to make a bump key better, you might also want to check out the following resources on bumping theory and the proper use of bump keys:

Note: Breaking and entering is illegal. This information in this bump key guide is meant for educational purposes and lawful use only.

Comments (24 Comments)

I am a 24 year veteran of a city ambulance service. These bump keys save people thousands in forced door costs. They, for me, work much better then any other lock pic I have used. No the city doesn’t repair your door because you fell and couldn’t get up or because your cat stepped on the panic button of your med alert while you were out shopping.

Posted by Boris on February 02, 2014

I think that bump keys should not be sold to anybody on the street.Being a ex police officer, I for see that this would lead to a lot of B&E’S. I am also a certified locksmith and I see this being a problem and I think before they sell to the public they should have a back ground check.

Posted by lockten on December 23, 2013

I lost my back door key what’s the best way to make a bump key the easiest way

Posted by tom on December 20, 2013

I have a question, im divorcing, still living in the same house and my soon to be ex has locked my stuff in the master bedroom, that he took as his, i would like to have a bump key, if i enter that room, would that be B&E? my lawyer also told me that i should have break that door long ago, so he is in control of my stuff and nothing i can do about it, i cant even pack my stuff cause he has them in that room. ill be looking for an answer.

Posted by Juana on November 05, 2013

Yes, I have copied a Schlage SC1 bump key on a Minutekey machine and successfully bumped open a lock with it. Furthermore, the original key was marked “do not duplicate” and human key machine operators had refused to duplicate it.

The Minutekey copy lacks the “do not duplicate” notation and can now be copied anywhere, although some human key machine operators may recognize it as a bump key and refuse to make copies.

Minutekey machines apparently cut the duplicate keys to factory specifications, correcting each notch to the closest standard depth and correcting the teeth between notches. Thus, the machine may produce a precision cut key from a hand filed key.

It may even be possible to file down the key flat to the maximum depth and have Minutekey cut the teeth on the copy. (Preserve the slope furthest from the tip of the key, so your hand filed key simulates a well worn key.)

Minutekey machines could be reprogrammed to recognize bump keys to reject them. When that happens, a work around would be to file one notch to the next highest factory height, make a Minutekey copy, and then hand file that notch to the desired height on the copy, also properly filing the adjacent tooth or teeth.

Posted by Master Unlock on October 23, 2013

I have a set of bump keys I purchased at DerbyCon. Has anyone tried to copy a bump key with those auto minutekey kiosks at Walmart or Lowes. It would be ideal if you have a set already. Has anyone tried this?

Posted by HeX on October 01, 2013

I am a Police Officer with three decades of experience. I own and use a lock pick set , a pry bar , bolt cutters and a slim jim. I do not have a bump key set but may get one. If you "Break " and enter a structure IE : do damage, it is one element of the crime ( Felony ) of Burglary ( often mis referred to as robbery ). If you enter a structure without causing damage ( lock pick ) and do not steal or damage anything within. This is Trespass in a structure ( Misdemeanor ).

Posted by Mike on September 21, 2013

I am not defending either side. But I think we are talking semantics here. Breaking and entering is illegal in the sense that if you do what those words say, it’s an illegal act. But in legalese, so to speak, it’s called other things such as burglary or illegal trespass. So, just because you aren’t charged with the colloquial “breaking and entering” doesn’t make it legal. But semantically it “isn’t illegal” just because it happens to be technically called something else. Let’s just apply common sense “a rose is a rose by any other name” seems to apply quite nicely. Just because semantically Phil is right he is still of course overall wrong because the actual act of what we know the words breaking and entering to mean in plain English is an illegality just by a different set of word(s)(i.e. trespass, burglary etc. which seems to be where determined intent comes in). In this case making them synonymous. My guess is Phil got this from the following (as exemplified by the “Law dictionary” at – for reference) “breaking and entering n. 1) the criminal act of entering a residence or other enclosed property through the slightest amount of force (even pushing open a door), without authorization. If there is intent to commit a crime, this is burglary. If there is no such intent, the breaking and entering alone is probably at least illegal trespass, which is a misdemeanor crime. 2) the criminal charge for the above.” Bottom line: it’s a “criminal act” (when unauthorized) despite what the words written on the paperwork are.

Posted by Spyder on August 02, 2013

wow your all so tough with your big guns! cops are so trig happy! and yet we pay these nut jobs to police us??? sorry boys but i dont believe b&e justifies murder! you need therapy, deal with your insecurity. If you break into my house and wake me up in the late hours, id prob try to sit you down on the couch smoke fatty and try to figure out how to solve your prob,and fuck it if you need my used electronics that bad homeboy have that shit but your packing it out! oh and thanks for using the lock and not breaking the damn window! ps insurance, i needed a new one anyways.

Posted by cant sleep at night on June 26, 2013

Not everyone using tools is a criminal. Securing abandoned foreclosed properties one frequently does not have keys as the bank does not have them. Breaking in is necessary and LEGAL and using tools to bump or pick is superior to having to break the door/doorframe or window which must subsequently be repaired and sometimes elicits alarm of the neighbors and an unneccesary visit from the police.

Think outside of the government provided thought-box sometime. The world is bigger than they tell you.
Posted by Ren on June 22, 2013

What about if you are married and your husband refuses to let you get your stuff? I was told that since we are married, I have every right to enter the home until we are divorced. Therefore it would not be B&E, right?

Posted by CrzySxy on June 21, 2013

Phil , I have been in Law enforcement for over 20 years, & ( B & E ) is a crime, you will be charged with B&E and booked ,so any one who listens to Phil,,,,,,Well if you don’t get shot then I will see you in Jail…..

Posted by escott on June 05, 2013

A lot of “lawyers” on this post I see. Intent is an element of B+E, and if you break in and are standing there without a reason when the cops show up, your intent will be implied. However, if you kick a window in to save someone from a fire, clearly there is no intent. Finally, if you walk through an open door but do not steal anything you are trespassing, which is a very minor offence. Simply really and common sense, and yes, I am a lawyer.

Posted by Escher7 on April 26, 2013

My father n law has been an attorney since 1960, the year I was born. As such, he’s been practing law for 53 years. B & E “IS” a crime. Think about it my man. What if I break into a home, walk all over the place but don’t touch anything have I assaulted anything or anyone? No. But what happens if the little 6 year little girl see’s me walking around in the dark? Did I assault her? No, not in a “physical” sense but mentally, who’s to say what such a scary sight might do to her mind. What do the people think when they wake up and find a window has been cracked or a door jimmied? B & E IS a prosecutional OFFENSIVE unless you live in in MASS. or are an ACLU dunce. 53 years of “Law” in Oklahoma if you B & E and get caught (If not shot) you can expect to be jailed and fined. NO, you won’t go to prison but, if is a crime non the less.

Posted by Dovehunter on April 07, 2013

I am afraid you are still incorrect with your defense against the other comments.

You state that the illegal part is “intent” after the B&E and that is false. Intent is not a crime, If you have broken into, and entered another’s property no other laws have been broken. Your intent once inside a home is irrelevant until you proceed to actually act it out.

Think of it like this, You can “intend” to murder someone you have a problem with, but you will not be charged with or convicted of murder unless you actually kill that person. If you go as far as to shoot that person, and they live, you still will not be charged or convicted of murder, it would be attempted murder.

You are on the right track, but “intent” is merely a principal, if you will that investigators and lawyers use to better understand a situation, and help in leading them to more evidence that will prove a crime is committed, and to paint a convincing picture to a jury.

If after you successfully B&E a private property, but then you simply turn around and leave the property, without taking, breaking, or assaulting anything, all the intent in the world (anything from dance naked in their living room to stab them all in the face) is irrelevant and it still won’t get you caught up with a charge, a case, or a conviction of anything more than trespassing.

So what I believe you meant to say was:
“What is illegal is the ACT after the B&E.”

Good try though!

P.S. I don’t want to rail you too hard since you have taken a beating already but another comment really shows your lack of knowledge on the subject. However please, please provide me with the proof if I am wrong, but in the history of this great country, I don’t believe anyone has ever had non-criminal B&E charges brought against them. I truly do not understand what I would be asking the officer. So please clarify A) What to your “knowledge” constitutes “criminal” and “non-criminal” B&E charges, and B) What the hell are you f**king talking about dude!? Do you even know?

Oh ya and nothing “can be illegal” (from your sentence: "the only thing associated with B&E that CAN be illegal..) It either IS or IS NOT illegal.

Phil, you INTENDED to sound knowledgeable and slick with your comment, but just ask any officer, are just a damn fool.

Posted by The Bionic, Ms. Kristonic on March 30, 2013

hi iam moonee from maldives ilike to be a locksmith or need to bye sometools like bumpkeyset and learning books/can u recumadat

Posted by moonee on February 04, 2013

This is one of those skills you need so you can better prepare yourself for the just incase situations

Posted by John on January 29, 2013

A treatise on crimes and misdemeanors, Volume 1
By Sir William Oldnall Russell

page 39

The circumstance of breaking and entering the house is common and essential to both the species of this offence ; but it does not of itself constitute the crime

Posted by sdrady on January 10, 2013

I see how many comments are about B&E, and no people shouldnt enter a home by lock picking, unless they are me. I’ll explain, I work for lender companies who have foreclosed homes, I am sent to do lock changes. What I have to do is drill out locks then install a new one. Its easyer to pick a lock to gain access than drill a lock. So for people who are doing the lock picking 100% legal, then it is ok. To enter a home to rob someone, then go ahead & shoot them. I pick locks only to secure the home with a new lock then winterize the home & leave. So not all lock pick buyers are doing illegal things with them.

Posted by ReKey on December 01, 2012


You are either a troll or a fool. Where I live, and in many other states, if you are a person whose intentions I fear and you come into my home without permission I have the right to assume you mean harm, and I can lawfully shoot you (Castle Doctorine) – which in the area I live is almost guaranteed to be the result of your entering any home. Furthermore, unauthorized entry is unquestionably B&E, and people are arrested for it with great regularity.

In any case, legalities aside, enter my home in the middle of the night, and when the dogs, large bore rounds, and I, are through with you, you will be welcome to make all the protests of legal loopholes you like.


Posted by urkiddinme on November 15, 2012

Phil: I’m afraid I’m going to have to side with SargeDude on this one. If you have information or legal precedent that demonstrates otherwise, please share your source for our edification.

Posted by Taylor on November 05, 2012

Are you out of your freaking mind??? B&E is entering property other than yours without permission – period!!!

Go ahead and enter my property and an officer’s response (MUCH different than the BS you profess) will be the least of your problems.

Posted by SargeDude on November 04, 2012

For the record. Breaking and entering is NOT illegal. Just ask any police officer. No one has ever had criminal B&E charges brought on them in the history of this great country. What is illegal is the intent after the B&E. That could be robbery, assault, etc… which carry charges like “attempted Robbery”, etc…

The only thing associated to B&E that can be illegal is

1. if you damage something or break break something you can be charged with vandalism.

2. you can be charged with trespassing if signs are posted stating No Trespassing.

but Breaking and Entering is NOT a crime in itself.

Posted by Phil on October 01, 2012

Great info thanks! I did buy just about all of.your BKs at Defcon though lol

Posted by matt on July 30, 2012

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