What Is the Difference Between a Single Cylinder and a Double Cylinder Deadbolt Lock?

Written By
Charm Baker
Charm Baker
Published: Nov 3, 2009
Updated: Nov 20, 2021
1 minute read
Not all locks are the same.

Function

Deadbolt locks are made to withstand amateur attempts at illegal entry. Typically the outer casing is made from hardened steel and resilient against hammer blows. Twisting these locks loose with pliers or a pipe wrench is no easy task either.

Types

The single cylinder deadbolt is the most common. It is found on front or back exterior doors and requires a key to open it from outside. A thumb turn opens it from the inside. A double cylinder deadbolt has no thumb turn. This prevents intruders from entering and exiting easily

Consideration

Not all deadbolts meet the Builders Hardware Manufacturers Association (BHMA) standards. “To assure you are getting the performance you specify. Look for the mark of Certification. Insurance companies recommend using single and double cylinder deadbolts that meet the ANSI Grade 1 specification.

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Warning

The double cylinder lock requires a key to enter or exit. This can prove hazardous in emergency situations. A missing key could be responsible for trapping someone inside.

Solution

Deadbolts with a captured key feature operate like a single and double cylinder lock. The interior thumb turn can be removed to create a keyhole. The last person out the house creates a double cylinder lock by removing the thumb-turn.

The Drip Cap

  • Using deadbolt locks is one way to help secure your home against intruders.
  • Look for the mark of Certification.
  • The double cylinder lock requires a key to enter or exit.
Charm Baker

Charm Baker resides in California, where she earned a journalism degree and began writing well over fifteen years ago. She has worked as both a staff and freelance writer for publications such as: Los Angeles Trade Winds, LA Kids, Minority…

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