Cable Ties - Tie Wraps

[MRehorst]

I've been poking around some web sites looking for info on proper tie-wrap usage. I can't find a thing on how to specify a size, how many to use for a given application, or reliability/lifetime. How tight is tight enough? How do tie-wraps react to elevated temperatures? Anyone know anything about any of these subjects?

I am trying to decide if cable ties alone are sufficient to hold components such as big electrolytic caps and maybe even toroid transformers to a chassis. My gut feeling is that tie-wraps are not sufficient, but it sure would be nice if they were...

Are the velcro-type wraps any more reliable that the solid nylon things? They would seem to be...

Thanks,

MR

[pinkmouse]

Hi MR

Assuming you mean the ratchet type,and as long as you don't use the piddly little ones, nylon cable ties are great. They are much stronger than you think, and are pretty heat proof, the only thing that kills them in my experience is UV light.

My only experience of the velco type is as cable tidies, for when cables are stored in coils. They don't like the heat, and the glue tends to go off after a while, resulting in a nasty, sticky mess.

[haldor]

Cops in the USA use nylon cable ties as expediant hand cuffs when they have a lot of people to deal with (riots, fraternity parties, etc). There is no way to break the larger ones without tools. Excessive heat does make them brittle with time and UV eats them up real fast.

To secure large electrolytics the metal bands are the best way to go. For smaller ones I like hot melt glue.

Phil

[Bobken]

Hi,

If you use the black coloured ones instead of natural nylon colour, they are resistant to UV light, as the manufacturers claim.

I sometimes doubt some makers' claims, but in this case it seems to be right as I have used some black ones on a rooftop aerial mast, and they are still OK after about 15 years.

In an alternative location at the top of the same mast, I needed to use some different sized ties which I only had in natural nylon colour, and these perished and failed after only two/three years.

Regards,

[crown300]

Most manufacturers specifify Cable tie specs(!) but it takes a lot of paitence to find the data. I just today spec'd a Panduit tie and their datasheet gives minimum diameter and maximum dia. along with minimum loop Tensile stregnth.(but doesn't give UL listing!)
goto;
http://www.panduiteeg.com/product_ca...oose_piece.asp
and drill down through:
Part Drawing and Requests
enter part number such as "BT2S" and then search "within catagory" and then click on the PDF file for "BT2S-C".
also not the FAQ at the first URL.
Please use a "Tie Rap Gun" as they pull the cable a certain amount of pull before cutting the cable tie. If you use a wire cutter without care you will leave a Razor sharp edge that will cut human skin when you reach into the chassies one day!
(boy, I'm long winded!!)

[GRollins]

They use scads of them around here (University of South Carolina Computer Services) to bundle cables. They don't fail here because they're under a steel false floor and there's no light down there.
They use some of the Velcro strap ties as well, although most things around here are fastened permanently...or until the next round of new equipment gets installed. They work great for guitar cables, though. I also use them to hold unused speaker cables. I've never used the straps for hardware. The squares with adhesive backs, I don't trust. As pinkmouse says, the adhesive tends to get gummy.
I've had the "blonde" cable ties fail due to light, and I've had the black ones fail due to either vibration or chemical action (undetermined). Still, they're pretty solid if you use one of sufficient width. I've seen them used in mid-fi stuff to hold power supply caps to the chassis. High end guys tend to use metal.
I'd say go for it.

Grey

Edit: Pittsboro, eh? I used to live in Chapel Hill.

[pinkmouse]

If you use a wire cutter without care you will leave a Razor sharp edge that will cut human skin when you reach into the chassies one day!

Yes, I can't remember how many times they have drawn blood! Now, I tend to just melt the ends briefly with a lighter, they round over and become safe

[fdegrove]

Hi,

MR...

I am trying to decide if cable ties alone are sufficient to hold components such as big electrolytic caps and maybe even toroid transformers to a chassis. My gut feeling is that tie-wraps are not sufficient, but it sure would be nice if they were...

As the name suggests this product was developped to fix cables together.

IMHO,don't use it to tie caps or other components to an even remotely complex PCB, not to mention multilayered ones.

First of all the plastics/nylon always relaxes a bit after tightening.

Second, when tightening there is the risk of flexing the PCB to the extend of causing cracks in the traces.

Thirdly,all the other aspects mention by the other members.

Fourth,the wrap will cause mechanical stress on parts that were not designed to carry that stress there.

Cheers,

[mbroker]

Originally posted by crown300
Most manufacturers specifify Cable tie specs(!) but it takes a lot of paitence to find the data.

Look for MS-3367. "MS" is a US Military Specification, which in this case is a set of specifications for cable ties. Yes, our tax dollars at work. Indeed the black ones will meet some rather stringent UV requirements. Don't ask how I know. . . .

As for strength, well, as the link above (click on "Cable Tie Part Numbers"), shows the tensile strength can be pretty strong! The typical "standard cable ties" are about .20" wide and have a tensile strength of about 50 pounds.

Using a couple cable ties to hold the large power supply caps to the chassis should be fine, IMO, so long as the chassis member can take the bending forces (read "thick sheet metal"). It may look kludged, but should function fine. However, I wouldn't know why one would want to use them to hold a transformer down since toroids have that nice mounting hole, and EI (plate) transformers have feet.

Regards,

Mark Broker

[MRehorst]

If you use tie-wraps to hold down a toroid transformer, you can get air flow through the center of the transformer.

MR