Help measuring diameter

A quick learner from Cleveland Ohio says:
August 2, 2017
Can u tell me which part of the spiral balance (pink arrow or blue arrow) I measure for the diameter so that I can order the proper replacement
parts. The metal ridged tube is 3/8 and the white plastic cover is 5/8. These are Alcoa windows from around 1994. Also for the length, do I measure the ridged metal or the plastic tube cover. Thank you!
Help measuring diameter
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Tom from SWISCO responded:
August 4, 2017
You want to measure the outer white tube for both diameter and length, indicated by the pink arrow. If yours is 5/8", then I would recommend our Series 600 spiral balance. This is assuming this is for a tilt window.
A quick learner from Cleveland Ohio says:
August 4, 2017
Thank you for the reply. Yes. It is for a tilt window. One more quick question, if the length of the whte tube measures 29.5 is it best to order a 30 inch or 29 inch.
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Tom from SWISCO responded:
August 8, 2017
I would bump it up to 30". Manufacturers used to make spiral balances on the 1/2", but those sizes have been phased out over the years. We find going up to the next inch is a safe bet.
30" Series 600 Spiral Tilt Window Balance
30" Series 600 Spiral Tilt Window Balance
S600-30
$9.40
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