Automotive Locks - Best Material for Tumbler Disc and Key

That's a good answer from Doorman. The reason for the use of brass is taht it's simply the best material for the job. The self lubrication factor is a real winner, as is the non-galling quality. The plastics also have some thermal stability problems, both in dimensional stability and in brittleness, particularly in low temp applications.

I appriciate your suggestion. But can we use stainless steel As per JIS 316. Bcz Cost of Stainless steel half of Brass and Stainless steel will serve our purpose also in term of mechanical strength as well corrosion resistance properties.

But I'm not sure whether manufacturing "key cutting" in stainless is possible not?

Please suggest.

I'm waiting for expert's view.

Bijoy Santra

Doorman, ktel60

Could he change the locks to stainless steel but keep the keys brass?

Hi,

usually: AlZn alloys for easy casting and limited self lubrication.

Or: AlCu (Al2024) or AlMgSi (Al6061) for high strength and medium to good anodising. Thick and hard anodised is equivalent to good sliding and low friction.

Any alloy shall be in STA status, may be over-aged is better than T6.

RHABE

I have another thought. I have re-read the original post: "We are in manufacturing of Automotives locks. Curently we are using brass material for both Tumbler Disc & Key. We want to replce this material from Brass to any other low cost material. Can any ony suggest me which material will be appropriate for this purpose."

There may be something I am missing in my previous comments. Bijoy, are you looking for help with the IGNITION keys?

If yes, please let us know. While my comments are correct in a general sense, most are not really applicable to the ignition keys of modern automobiles.

Hi Mr.Doorman,

Thank you very much for your quick & valuable response. Firstly, sorry to late response from my side. You are right that we are using the key in Ignition Switch Cum Steering Lock.

Secondly, we are using "Disc type tumbler" instead of "Pin type tumbler". Both Tumbler Disc & Key are made of Brass. My query was: are there any other suitable low cost material which can replace this brass, so that overall cost of the switch will be reduced without affecting its performance.

Bijoy Santra

Hello again, Bijoy Santra

I assume you are making an aftermarket (replacement) switch for older autos. That is to say, there are no transponder heads involved.

Locksmith Al said it completely and well: brass (or bronze) is used widely because it gives long service with satisfactory results. This has been so for many years.

You ask "are there any other suitable low cost material which can replace this brass, so that overall cost of the switch will be reduced without affecting its performance." The short answer, I believe, is no. I agree with Locksmith Al that SS parts (keys, in particular) will result in many problems. As my first comment, Aluminum (with some alloy) is used for parts in some cylinders with proven success. If you do this, the shell and plug can (possibly) go to ZAMAK 3 or ZAMAK 7 (http://en.wikipedia.org/wiki/Zamac#Uses), or some similar material. Are not these parts the larger consumer of metal for your cylinders? Zamak would probably not be suitable for keys and discs.

For the disc tumblers, brass is the ideal, with nickle silver running a close second.

STRATTEC here has aluminum wafers, they work, but they are subject to corrosion due to moisture, and in any kind of an alkaline environment will all but dissolve in short order.

HuF in Germany has used brass wafers in their locks, but steel keys, they work well, except for wafer wear over time.

Stainless keys are out of the question. The cutters used in locksmithing shops and the like are for the most part M2 carbon steel,and a stainless steel key is instant death on them.

Likewise with the equipment to cut a key using a punch and anvil to make the cuts. The tonnage needed to cut them in this manner is all but impossible for hand operated devices.

There's a reason brass and its alloys have been used for years in this application--it works!

Al

Auto Locks now use ALUMINUM wafers. This is an EDICT from government, not because it was found superior.

My preference on keys is STEEL. They are less prone to twist and breakage, and still can be cut on normal equipment.

MOST locksmiths in the US hate steel keys.

IMPROVING your designs to be better than the competition STRATTEC, ORTEC, HUF and others, should be top priority.

Moving factories to China and shaving cost will only be temporary, as car makers will go back to whomever can produce on-time delivery in the quantity required, and without the disasters that have occurred with poor designs/materials of the past.

In an auto lock, a little brass or aluminum goes a LONG way. Production savings through energy management and modern facilities that can change up processes faster should yield more savings.

If you develop a backward compatible cylinder, of sidebar design for GM that does NOT use a staked on spring-cap, you will have a winner. But it must be more durable than a Chrysler one, as those have a superior assembly, but high failure rate of jammed up wafers.

The world is also seeking a re-engineered replacement for ROVER ignition locks. A better cylinder design that does not fail out, and one that is modular for future serviceability.

You were vague as to your venture... OE CAR locks? SUV/Utility switches, or aftermarket auto?

Need a real-world, non laboratory peer-review on new designs? Happy to report on findings from prototypes.

Jeff

The Locksmith

The is NO EDICT from the government as to using aulminum instead of brass.

This is from a letter to all wholesalers from STRATTEC as to the productions changes and the reasons behind these changes.

I'll be more than happy to forward the letter and e-mail from STRATTEC as to their reasoning behind their decision, and it would be appreciated if individuals got their facts straight before posting conjecture on their part as fact or law.

February 2, 2005

STRATTEC is currently in the process of complying with a new requirement from General Motors, Ford, and Daimler Chrysler that requires us to remove hexavalent chromium from all our processes. For STRATTEC, the plating process is the area of change, and STRATTEC has chosen to move to a trivalent chromium process. This change will affect all cast and stamped components. We have also decided to replace most of our brass tumblers with aluminum tumblers, to maximize the performance related to the move to trivalent.

How does this affect you? In the coming year, you will see a change in color to your cast and/or stamped components contained in lock service packages as well as individual purchased components such as tumblers, cylinders and pinning kits.

Will there be a cost increase related to these changes? No. The cost incurred by these changes is not being passed on to you.

Is STRATTEC requesting a part number change? No. You can continue to order parts using the same part numbers. The changes will be handled as "running changes".

Is there a performance/capability issue between hexavalent, trivalent, brass and aluminum? All our testing shows that all four combinations of hex/brass (the current process), hex/aluminum, tri/brass, and tri/aluminum all pass the current OE automotive corrosion standards.

Will there be any issue with the mixing of brass and aluminum tumblers in the same lock while repairing? All testing indicates that the performance of the lock will not be affected when both brass and aluminum are used in the same lock.

If you should have any questions regarding these changes, please direct them to Fred Kosloske at 414-247-3331, Jeff Baker at 414-247-3421 or Vera Latus at 877-251-8798.

Thanks for your continued support of the STRATTEC product.

Al, consider the following:

__________________________________

Steps OSHA has taken to protectemployees from health hazards causedby hexavalent chromiumThe new OSHA workplace standard requiresemployers to:• limit eight-hour time-weighted average hexavalentchromium exposure in the workplace to5 micrograms or less per cubic meter of air.• perform periodic monitoring at least every 6months if initial monitoring shows employeeexposure at or above the action level (2.5micrograms per cubic meter of air calculatedas an 8-hour time-weighted average).• provide appropriate personal protective clothingand equipment when there is likely to be ahazard present from skin or eye contact.• implement good personal hygiene and housekeepingpractices to prevent hexavalentchromium exposure.• prohibit employee rotation as a method toachieve compliance with the exposure limit(PEL).• provide respiratory protection as specified inthe standard.• make available medical examinations toemployees within 30 days of initial assignment,annually, to those exposed in an emergencysituation, to those who experience signsor symptoms of adverse health effects associatedwith hexavalent chromium exposure, tothose who are or may be exposed at or abovethe action level for 30 or more days a year, and

at termination of employment.

_______________________________

This is an excerp from an OSHA publication.

Read the full publication at

http://www.osha.gov/OshDoc/data_General_Facts/hexavalent_chromium.pdf

I take that as a GOVERNMENT EDICT, if there ever was one !

And if you knew your metallurgy, you would know that there is NO chromium, hexavalent or otherwise, in brass.

Ergo, no Government edict, as I stated.

Locksmith Al

Al,

"there you go again" lol

I am not saying there is a particular chemical in a particular finished product. But I can connect the dots.

Three major mfrs all come up with this requirement, if not for the fact the the manufacturing process of certain parts, requires presence of such chemicals, either as a lubricant or for other purpose; thus exposing employees to an unacceptable risk... this results in a GOVERNMENT edict, order, threat of suit or other pressure to change a practice to fulfill this "risk" abatement, be it real or imagined.

Subcontractors have to abide to the contractor, and meet all government requirements, so the easy change is to go to aluminum.... less hassle.

I see the argument is not over what is in Brass, but the process or facilities that produced the product.