Is there a standard for pen turning bushes?

[flh801978]

Is there an expected size for the internal diameter of pen bushings?

 

[Blister]

Is there an expected size for the internal diameter of pen bushings?

Error in my post so removed

 

[clogs]

getting the guts at a decent price would also help.....
it's never one size fits all I'm afraid....
more money for tools.....

 

[Inspector]

Pen mandrels are often referred to as 7mm as that is the size of the hole you drill to fit a 7mm tube (actually a touch smaller or it wouldn't go in the hole) for kits like the slimline. The actual size of the mandrel is 0.247"+/- 0.001"(6.274mm) depending on the seller. The bushings that slide over the mandrel are a touch bigger or they wouldn't fit.
Did that help or muddle you up more?

Pete

 

[flh801978]

Well i have always thought that the mandril was 1/4” 0.25”
But apparently some bushings are to fit on a 6mm mandrill so wont fit on a 1/4 shaft

 

[Phil Pascoe]

Mandrels sold in this Country are 1/4", all the ones I've seen on Banggood etc. are 6mm - which British bushes won't fit.

 

[Inspector]

To be honest I avoid the entire mandrel/bushing size stuff by turning between centres (TBC). I use stock bushings to get close to size and then remove them and finish off between the centres only, checking the sizes with a caliper. Might take a few minutes longer but I don’t have any out of round problems either.
Pete.

 

[Lons]

Phil is correct mandrels are not 7mm (not in the UK anyway), you drill a 7mm hole in the blank to suit the outside dia of say a slimline tube. However even though 1/4" is standard or more often 6.25mm which is slightly less, they are often not especially accurately machined, bushes can vary a bit as well.

 

[Dalboy]

It all depends on the pen kit and where it is from as the bushes are drilled out (As already stated) with either a 1/4" hole of a 6mm. Some that I have brought in the past from Axminster tools have had the 6mm which I drilled out to 1/4" as that is my mandrel size. I have however gone to turning between centres using some tapered bushes and measure the kit and turn to that it save having to buy bushes every time I turn a new pen design.
And now if I do decide to make a run of pens I can turn up my own bushes

 

[Blister]

And now if I do decide to make a run of pens I can turn up my own bushes

That's a good point

 

[Phil Pascoe]

I find these invaluable for comparative measurements (even if they have gone up £3 in less than a couple of years).

https://www.amazon.co.uk/Stainless-...oogshopuk-21&linkCode=df0&hvadid=275572147651