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spinrow
01-01-2013, 10:01 PM
I was looking in a hardware catalogue trying to decide what hardware I needed for a current project. For example:I saw there are inside and outside serrated washers and am looking for a book that would tell me under what circumstances I would use one type rather than the other. Anyone have a recommendation for a book or other source of information. Thanks Paul

alchymist
01-01-2013, 11:15 PM
Serrated lock washers come in three types - internal tooth, external tooth, and both internal/external. Internal tooth washers are used where a clean appearance is desired, while the external tooth and the internal/external tooth style are used for maximum locking effect.

The objection to serrated washers is the proclivity of tearing up the surfaces to which they are applied, more so than a split lock washer.

They are preferred in electrical applications, as they provide a better contact between mating surfaces.

Paul Alciatore
01-02-2013, 01:07 AM
One of the best catalogs for hardware parts is McMaster-Carr. They often have short explanations about the characteristics of the items on the catalog pages. In some cases, they have a full page or two of explanation preceding a section of the catalog so searching backwards is often rewarded. They have a paper catalog, but unless you are listed as a large company, getting one is problematic. But they have the best on-line catalog in the world, bar none in my humble opinion.

You can search for any item by it's description, dimensions, or other specs. Unlike some on-line catalogs, they do NOT list useless categories like manufacturer, model number, etc.

http://www.mcmaster.com

After searching for an item and narrowing it down with their spec based categories, you will see a reference to the catalog page on the search results. Follow it and you can get more information that is in the printed catalog. Here is one of the pages for lock washers.

http://www.mcmaster.com/#standard-lock-washers/=kus6ic

All the usual disclaimers.

oldtiffie
01-02-2013, 01:21 AM
Those serrated washers are a form of "shakeproof" washer intended to stop the nut undoing/reversing.

http://en.wikipedia.org/wiki/Washer_(hardware)

http://www.google.com.au/#hl=en&sugexp=les%3B&gs_rn=1&gs_ri=hp&cp=11&gs_id=16&xhr=t&q=serrated+washer&pf=p&tbo=d&output=search&sclient=psy-ab&rlz=1R2IRFC_enAU360&oq=serrated+wa&gs_l=&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.&bvm=bv.1355534169,d.dGY&fp=620d012bf938acf7&bpcl=40096503&biw=1280&bih=545

http://www.google.com.au/#hl=en&sugexp=les%3B&gs_rn=1&gs_ri=hp&cp=11&gs_id=16&xhr=t&q=serrated+washer&pf=p&tbo=d&output=search&sclient=psy-ab&rlz=1R2IRFC_enAU360&oq=serrated+wa&gs_l=&pbx=1&fp=1&bpcl=40096503&biw=1280&bih=545&bav=on.2,or.r_gc.r_pw.r_qf.&cad=b

1-800miner
01-02-2013, 09:58 AM
+1 for McMaster Carr. I like their search engine. Four or five mouse clicks and you are looking at your item.
I went to Graingers site and gave up. Could not find what I wanted and it was a common item.

fjk
01-02-2013, 10:28 AM
+1 for McMaster Carr (to be redundantly repetitive)
They also are happy to deal with in small orders and for private individuals.

Getting their printed catalog seems to be difficult (I've never found it anyway)

MSC carries basically the same stuff, and they (used to) make their printed
catalog available for free.

Frank

Dunc
01-02-2013, 11:01 AM
Caroll Smith's Nuts, Bolts, Fasteners & Plumbing Handbook, Caroll Smith, Motorbooks, 1990, ISBN 0-87938-406-9 has a lot of info.

Here is a link to an updated version (that I have not examined):
http://www.amazon.com/Carroll-Smiths-Fasteners-Plumbing-Handbook/dp/0760341036/ref=sr_1_6?s=books&ie=UTF8&qid=1357138774&sr=1-6&keywords=carroll+smith

Usual disclaimers

joe51
01-02-2013, 12:31 PM
Serrated lock washers come in three types - internal tooth, external tooth, and both internal/external. Internal tooth washers are used where a clean appearance is desired, while the external tooth and the internal/external tooth style are used for maximum locking effect.

The objection to serrated washers is the proclivity of tearing up the surfaces to which they are applied, more so than a split lock washer.

That's why for most applications you're supposed to use flat washers under them, especially on soft materials such as brass and aluminium.

"They are preferred in electrical applications, as they provide a better contact between mating surfaces."

Toothed lock washers actually provide two benefits when used in electrical connections. First, electrical connections tend to heat up and then cool every time power is turned on and then off. The expansion/contraction tends to make them unscrew themselves which in turn causes poor connection which makes heating/cooling even more severe until it eventually causes localized overheating and possible a fire. Second, they also help prevent poor connection since the teeth dig into to both conductors and will also carry power even if conductors aren't touching each other. They have an advantage over spring lock washers in that they have many teeth to carry power instead of just one.

MichaelP
01-02-2013, 02:09 PM
You may want to be a test pilot for the new Fastener Black Book: http://www.fastenerblackbook.com/
Please provide your feedback for us.

PeteM
01-02-2013, 06:45 PM
Automakers and others who actually study this are using less and less lock washers. Turns out that a properly tensioned nut and bolt are highly resistant to working loose. If there's significant vibration, a Loctite equivalent is often best. Lock washers, especially when stacked with regular washers, add uncertainty to torque/tightening and may interfere with full contact of the bolt head or nut and part.