Master 175 Lock Picking Tip*

Master 175 Lock Picking Tip*

Writing this article for TWO reasons, so you don’t waste your time and so you don’t look like an idiot. Because I care, just like the government. (Rotfl, I do care but obviously kidding about the government part)

How it works

When you purchase a Master 175 it comes with a tool that looks like a key but isn’t.

(Above) Master Lock 175’s (and many other 4-digit padlocks) come with a Factory Code set on them: 0-0-0-0

(Above) This is not a “Key Way” with pins in it. It is not used to unlock your M175. It is a tool to change the combination on your lock only once the lock is opened.

Processed with MOLDIV

(Above) Once your lock is open and unlocked you insert this “Tool” (notice I didn’t say key) into the tool-slot and turn it to the right a quarter turn.

(Above) With the tool inserted and turned you can now change your combo code from 0-0-0-0 to any other 4 digit code that you want. Once your new code is set you can un-turn your tool and take it out of the tool-slot. All done, new code.

4-Digit Codes

I teach an entire content block in my Urban Survival Course* on “4-Digit Codes”. I am also currently working on my new book (working title) “Tactical Lock Picking” and that will be a chapter in the book as well. Here is a quick crash-course on 4 digit codes you may want to consider.

4-Digit Codes as “Traffic Control Devices”

Traffic lights do not stop people that are getting from A to B. They just create a variable momentary pause in your travels, much like any 4-digit combo lock or a 4-digit key pad. As security is always a balance between thorough and convenient one of the biggest reasons people USE 4-digit codes on locks, instead of using a key, is because multiple people need access to the same lock. What does that mean for us, the ones breaking in (legally breaking in of course)? There are several categories that codes fall into which can help us determine how to guess a code.

  1. Factory Reset Code (FRC) – If you have a make and model of the lock or key pad you can often Google the product manual and look up exactly what the factory reset code is. This one is often a good starting place.
  2. Common Access Codes (CAC) – There are lists of this online, as well as resources in my upcoming book, that will list x-number of codes that follow certain patterns. Examples are:
    1. 0-0-0-0; 1-1-1-1; 2-2-2-2; etc.
    2. 1-2-3-4; 2-3-4-5; etc.
    3. 1-3-5-7; 2-4-6-8; etc.
    4. 0-9-8-7; 9-8-7-6; etc.
  3. Socially Engineered Codes (SEC) – Codes that mean something for the person or the place that the lock is used for. Most commonly:
    1. Last 4 of the lock owner or locations Phone #.
    2. Last 4 of the owner’s Social Security #.
    3. Last 4 of the owner or location’s address.
    4. Birthdays of self spouse or children, Anniversaries, Military Branch Est. Dates (ask me how I know):
      1. DD/MM
      2. MM/YY
      3. YYYY     etc.
  4. Random Ass Codes (RAC) – These are a problem. These are very difficult to guess if you are using a blind guess method like trying the FRC and then all the CACs and then going down your list of SECs, you may be stuck with the “Add 1” method if you haven’t had any success yet.
  5. “Two Step Rule” – While this is not a “Category of Types of Codes” it is a method to consider when trying to gain access somewhere. I have VERY MANY case studies that a code will be written down (or online) within two-steps of the lock or key pad; written on the device itself, written on the wall, on a post-it-note in a drawer nearby, etc. So check your surroundings and look for 3-digit stings of numbers and add a zero to the beginning or end, look for 4-digit strings of numbers or more and use the last 4.
  6. “Evidence” – Also not a “Category of Types of Codes” but it is a method to use when attempting to gain entry. This one is pretty Jason Bourne-ish but it happens all the fucking time in real life. Especially if a code is used by a large number of people it often will be a bureaucratic pain in the ass to notify 400+ people of a code change. Which MEANS that the code on key pads and on mechanical locks will literally have the answer worn into the device!


Hopefully with all the knowledge I share on this website and on my podcast you can start to ask yourself some questions and determine what type of security you use and if it is reasonable. There is no such thing as perfect security but you can often do better if you are better informed.

If you found any value in today’s article then please Subscribe HERE, and always feel free to drop me a line on my Contact Form HERE.

Be safe, question everything, stay LEGAL.


Leave A Reply