How to Use a Tension Wrench for Lock Picking

How to Use a Tension Wrench for Lock Picking

The tension wrench is the most important tool in lock picking. Not the pick.
The wrench.

You can sometimes open a lock with just a tension tool, but you’ll never open one with only a pick.

This guide teaches you how a tension wrench works, how to control pressure, how to read feedback, and how to practice legally on personal locks or clear training locks.

What a Tension Wrench Is

A tension wrench (also called a torsion wrench or turning tool) is:

• A thin piece of metal

• Bent into an L or Z shape

• Designed to fit inside the keyway

• Used to apply rotational torque to the lock

Tension Wrench:

• Replaces the key’s turning pressure

• Holds pins at the shear line

• Provides feedback through your fingertips

• Controls everything about the pick process

If the pick is the “probe,” the tension wrench is the engine.

Types of Tension Wrenches

L-Shaped Wrench (Standard)

• Strong and simple

• Works on most keyways

• Good for beginners

Z-Wrench / Double-Ended Wrench

• Two thicknesses in one tool

• Fits tight or wide keyways

• Great for EDC kits

Top-of-Keyway (TOK) Wrench

• Rests in the top of the lock

• Very stable

• Great feedback

Bottom-of-Keyway (BOK) Wrench

• Most common

• Works with almost every lock style

Compact EDC wrenches, such as those on Grim Workshop cards, provide the same function in a lightweight, thin form factor perfect for practice locks and low-torque environments.

How a Tension Wrench Works

When you insert the wrench and turn gently, you create:

• Rotational tension

• Binding order (pins bind one at a time)

• Shear line alignment

• Feedback through vibration and resistance

Too much tension → pins won’t move.
Too little tension → pins drop back down.

Finding the perfect middle ground is the goaHow to Hold a Tension Wrench

Finger Pad Grip

Best for beginners — light pressure, high control.

Feather Touch Grip

Hold wrench with only fingertips.
Lets you feel tiny clicks and pin movement.

Thumb Lever Grip

For locks requiring slightly more pressure.

Reverse Grip

Used when applying tension from the opposite direction.

How to Insert the Tension Wrench

Bottom-of-Keyway Method

Start here:

1. Insert wrench at the very bottom of the keyway

2. Ensure it doesn’t block your pick

3. Apply light pressure in the direction the key turns

Top-of-Keyway Method

Useful when:

• You need more control

• The bottom is too tight

• Lock has security pins

Insert the wrench at the top shoulder of the keyway.

How to Apply Tension (The Core Skill)

Step 1: Insert Wrench

Place it firmly but gently.

Step 2: Turn Slightly

Apply a tiny amount of rotation.
Think the weight of a pencil.

Step 3: Hold That Tension

Keep your tension stable as you begin picking.

Step 4: Adjust Tension as You Pick

• Too tight? Ease up

• Too loose? Increase slightly

Step 5: Feel for Feedback

You should feel:

• Clicks

• Resistance

• Movement

• Changes in torque

This is the “communication” between lock and fingertips.

Understanding Binding Order

Pins bind one at a time in a specific order based on:

• Manufacturing tolerances

• Wear

• Lock design

Your tension wrench creates this binding order.

You pick whichever pin binds first — then the next — until all reach the shear line.

How to Use the Tension Wrench While Picking

1. Standard Pin Setting

Workflow:

1. Insert wrench

2. Apply light tension

3. Use pick to lift first binding pin

4. Feel for click

5. Move to next binding pin

6. Continue until lock rotates

2. Raking With a Tension Wrench

For rake picks like snake, city, or jiggler picks:

1. Insert wrench

2. Apply slightly firmer tension

3. Rake pins rapidly

4. Release tension briefly

5. Tighten again until lock turns

Pairs with:
→ Using Your Rake Lock Picks

→ Using Your hook Lock Picks
→ All Tools with Lock Picks

3. Using a Tension Wrench for Overset Recovery

If a pin oversets:

1. Ease off tension

2. Allow pins to drop

3. Reapply controlled pressure

4. Continue picking

4. Testing Keyway Direction

If you don’t know which way the lock turns:

1. Insert wrench

2. Apply light tension in one direction

3. Try slight pressure in the opposite direction

The correct direction typically:

• Feels smoother

• Allows slight rotation

• Feels less “stiff”

How Much Tension Is Correct?

This is where most beginners struggle.

Light Tension

Best for:

• Standard pins

• Soft springs

• New locks

Medium Tension

Best for:

• Worn locks

• Old hardware

• Door locks with weak tolerances

Heavy Tension

Rarely used — typically only for:

• Stuck cylinders

• Binding cores

• Locks with internal grime

Most of the time, beginners use too much tension.

If nothing is moving, lighten up.

Advanced Tension Techniques

Feathering

Micro-adjusting pressure while lifting pins.

Pulsed Tension

Tiny pulses while lifting each pin to feel movement.

Reverse Tension Picking

Used when security pins falsely set.

Floating Tension

Maintaining constant but adjustable torque based on feedback.

Using a Tension Wrench With Security Pins

Security pins include:

• Spool pins

• Serrated pins

• Mushroom pins

Your tension wrench lets you feel:

• Set

• False set

• Counter-rotation

• Shear line alignment

This requires practice on clear training locks.

How to Practice With a Tension Wrench

Use a Clear Practice Lock

Lets you see pin movement while learning tension.

Try Different Wrench Thicknesses

Different locks prefer different fits.

Rotate Directions

Practice clockwise and counter-clockwise.

Master Light Tension First

It's 90 percent of skill.

How to Improvise a Tension Wrench

If you’re practicing and don’t have one:

1. Paperclip (Flattened)

Bend into L shape.

2. Street Sweeper Bristle

Excellent spring steel.

3. Small Flat Screwdriver

Works in larger keyways.

4. Thin Scrap Metal

Trim and bend with your bending tool.

Common Beginner Mistakes

• Too much tension

• Changing tension during picking

• Blocking the keyway

• Not identifying binding pin

• Oversetting

• Ignoring counter-rotation

• Holding wrench too tightly

• Using wrong wrench thickness

Expert Tips

• The wrench tells you everything — trust your fingertips

• Use just enough tension to bind the first pin

• Ease up the moment pins stop responding

• Try top-of-keyway tension for better feedback

• Treat tension like volume control — adjust constantly

• With practice, you’ll feel the lock before you see it move

FAQ

Q: How much tension should I use?
A: Usually less than you think — start with very light pressure.

Q: Can I open a lock with just a tension wrench?
A: Certain cheap locks can be bypassed with tension alone, but this is uncommon.

Q: What is the best wrench thickness?
A: Medium thickness fits most locks. Thin wrenches work for tight keyways.

Q: Does the wrench go on top or bottom?
A: Both work — bottom is easier for beginners, top gives cleaner feedback.

Related Skill Series Posts

• → Using Your hook Lock Picks

• → Using Your Rake Lock Picks

• → All Tools with Lock Picks

• → All Items with a tension wrench

(© 2025 Grim Workshop. All Rights Reserved. Grim Workshop, Survival Cards, and all related marks are registered trademarks of Grim Workshop. This article is part of the Grim Workshop Skill Series educational archive. No content may be reproduced, republished, stored, or adapted without written permission. For compact lock picking tools, tension wrenches, and EDC practice lock kits, visit www.grimworkshop.com.)