Helicoil versus Time Sert

I've used helicoils for years and always got satisfactory service from them. However I recently stumbled upon Time Sert thread repairs:
http://www.denlorstools.com/shop/wpi...Comparison.jpg
Has anyone ever used them and what do you think? Supposed to be stronger, but I always thought helicoils actually improved the strength of thread in light alloy or cast iron.... Also I do see how that collar allows for flush mounting of a (say) mating surface.
Anyway, I'd be interested in the pros and cons of these things - are they just an answer to a problem that doesn't exists or a way around some patent?
Julian.
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Not used them, but I would think that most of the advantage over helicoils is ease and speed of insertion, which only matter on the production line; reading between the lines of the blurb that seems to be the case. I can't see much prospect of any increase in strength; pullout resistance is usually governed by the strength of the base material or the fastener, not the insert. The extra cost isn't really justifiable for hobby use, but you may feel differently. It can't be a way round the Helicoil patent, because I have a box of Australian made Helicoil-u-like copys in the shed which seem to work on the same design.
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I've seen similar things that sleeve down a threaded hole. So if you strip an M10, you tap it M12 and screw in an insert to reduce it back to standard. That saves the cost of the tap but it takes up more space. As for any advantage over helicoils, well price certainly isn't one. They look solid rather than Helicoil's wound design. That would make them stronger when there's not full thread engagement. They may also be less prone to virbrational issues as the insert is solid. Other than that, I can't see anything better about them.
John
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Thanks John and penfold - pretty much as I thought. I won't bother with them until they appear in the Unithread catalogue :-)
Julian.
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