# sprial flush trim bit



## dogrunner (Mar 6, 2011)

whats a good on to get iv been doing a lot of patteren routing and think its time to up grade .how long do they stay sharp for thanks


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## Quillman (Aug 16, 2010)

Stays sharp ~2-4x longer than brazed-on carbide but still the 1/2 life of carbide under duress is<300'!!
1/2" cutting diameter tools are short lived no matter what their composition (save PCD).
Would be looking at @WMC's new 3/4" CD trimmers if you want the best.
More on spirals, see no 12.


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## Phil P (Jul 25, 2010)

Quillman said:


> Stays sharp ~2-4x longer than brazed-on carbide but still the 1/2 life of carbide under duress is<300'!!
> 1/2" cutting diameter tools are short lived no matter what their composition


That's partly why I tend to do as much template work as possible with one of these - replaceable tip carbide, 19mm (3/4in) diameter. They run cooler, especially on plastics, you never hace to send them out for sharpening - just swap the tips with a Torx key (supplied) - and if you smash-up a tip or two on an inclusion (as in particle board, etc) it hurts a lot less in the pocket. Not sure why but they seem to last longer and be sharper initially tha brazed tip tooling

Regards

Phil


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## jschaben (Jun 21, 2009)

Phil P said:


> That's partly why I tend to do as much template work as possible with one of these - replaceable tip carbide, 19mm (3/4in) diameter. They run cooler, especially on plastics, you never hace to send them out for sharpening - just swap the tips with a Torx key (supplied) - and if you smash-up a tip or two on an inclusion (as in particle board, etc) it hurts a lot less in the pocket. Not sure why but they seem to last longer and be sharper initially tha brazed tip tooling
> 
> Regards
> 
> Phil


Hi Phil - I've got one of those made by Amana. Would like to have more but they're kinda spendy over here for hobby use. The blades do hold their edge very well. The story I got on that is a much harder grade of carbide is able to be used on replaceable blades because they don't need to undergo the brazing process. Can't say if that makes practical sense or not but sounded good to me.:blink:


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## bobj3 (Jan 17, 2006)

Hi Phil

How about a real picture of the ones you have on hand ,,,,would love to see how they hold you,,like they say a picture is worth a 1000 worlds..plus a shot of your Van would be nice..sounds like you have a 40ft long Van. for your shop and tools.

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Phil P said:


> That's partly why I tend to do as much template work as possible with one of these - replaceable tip carbide, 19mm (3/4in) diameter. They run cooler, especially on plastics, you never hace to send them out for sharpening - just swap the tips with a Torx key (supplied) - and if you smash-up a tip or two on an inclusion (as in particle board, etc) it hurts a lot less in the pocket. Not sure why but they seem to last longer and be sharper initially tha brazed tip tooling
> 
> Regards
> 
> Phil


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## Phil P (Jul 25, 2010)

bobj3 said:


> How about a real picture of the ones you have on hand ,,,,would love to see how they hold you,,like they say a picture is worth a 1000 worlds..


Is it really, Bob? And there was me thinking that use of the English language hadn't died! Oh, well......










As you obviously unaware, the three cutters on the right are TC-RT trim bits, 1/2in shank. Centre to right they are:

- template trim 28.5mm (1-1/8in) diameter x 24mm (15/16in) high (T8112B-1/2 £37.85)
- template trim 19mm (3/4in) diameter x 12mm (15/32in) high (T8115B-1/2 £32.15)
- multi-trim with top and bottom bearings 19mm diameter x 20mm (just over 3/4in) high (T8145B-1/2 £38.10)

all from Wealden Tool in the UK. I'm sure there will be suppliers in the USA who do something similar (Wealden buy-in, probably from Israel). Cutters like these cost no more than a 3/8in (9.5mm) spiral solid carbide, BUT the big plus is that replacement tips cost only £1.70 to £3 (US$3 to $5) each, less than the cost of sharpening a brazed cutter, and you can often find even better deals if you scout around on eBay, etc. So as soon as you need to sharpen a spiral (say after 300 to 500ft of cutting) these cutters start to make make a lot of financial sense, especially as all the tips are double-sided so you get a "free" sharpening with each pair of tips! The 12mm square tips as on the middle one are even cheaper - they are 4-sided (and I got my last box of 10 tips for about £12 or US$18 - so 20 sharpenings for under $1 a pop makes them pretty cheap to run). I suppose it all depends on how much you actually use a router. I have these because when I'm doing templating work I tend to be doing a large volume and the cost saving is well worth it

For anyone interested the cutters on the left are deep pocket cutters for deep mortising, left to right they are:

- 16mm (5/8in - T2126-1/2) diameter (brand new)
- 12mm (15/32in - T2121-1/2) diameter (brand new)
- 12mm diameter (T2121-1/2) after about 15 or 16 lock mortises.

They all come from the same supplier, Wealden Tool, and are designed for use with the Trend lock jigs

Please note that on the prices I've given an approximate conversion. In reality US prices should be even lower - size of the market and UK prices include 20% Sales Tax (VAT) which tends to inflate our prices against yours (which I believe are always quoted ex-sales Tax)

Regards

Phil


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## dogrunner (Mar 6, 2011)

what kind of finish do the replaceable carbid bits leave


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## Phil P (Jul 25, 2010)

dogrunner said:


> what kind of finish do the replaceable carbid bits leave


A bit better than a good quality brazed carbide bit (after all, they're sharper and harder) but not quite as good as a spiral. In other words more than acceptable. I don't find that an issue because at the end of the day you pretty much always need to sand out anything you machine. They outlast either by quite a bit, IMHO, so over time they pay for themselves

Regards

Phil


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## bobj3 (Jan 17, 2006)

Thanks Phil

IMHO the SOLID CARBIDE & SPIRAL Trim bit is the best way to get a nice clean edge/cut no sanding needed the norm..

MLCS solid carbide router bits

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Phil P said:


> Is it really, Bob? And there was me thinking that use of the English language hadn't died! Oh, well......
> 
> 
> 
> ...


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## Phil P (Jul 25, 2010)

bobj3 said:


> SOLID CARBIDE & SPIRAL Trim bit is the best way to get a nice clean edge/cut no sanding needed the norm..


It depends. Bob. By sanding I don't mean hours spent doing the job, just a single pass with a sanding board or past an oscillating bobbin. This is fairly normal in production routing because even with the best cutters there are scallops left (as well as, potentially, fibre compression marks, especially as the cutter dulls) which whilst they are invisible to the naked eye can and will show up when you apply any finish. The wetting of grain by the finish will inevitably result in grain being raised (at least with timber and man-made timber product boards) which in turn will require flatting back of the edges at this stage unless you wish the inevitable ripple edge effect (as seen in much modern millwork) to be annoyingly apparent under oblique lighting. Products such as MDF are particularly prone to this. Whilst spirals are better in this respect, but they still produce the scallops and I know of no production shop where finishing straight off the tool is done unless a high-build undercoat is being applied. That is a production-orientated response and is only what you could expect to hear from many wood machinists

Regards

Phil


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