In plain English
FAR 52.211-17, Delivery of Excess Quantities, is a contract clause prescribed at FAR 11.703(b), most recently dated Sept 1989. The complete official text is reproduced below, verbatim, from GSA's published FAR source files.
Its text contains no sentence requiring insertion into subcontracts; see the flowdown section below for what that does and does not mean.
Does it flow down to subcontracts?
No flowdown mandate found in the clause text
We scanned the full clause text and found no sentence directing the contractor to insert this clause into subcontracts. That is a statement about the text, not legal advice: a prime contractor may still flow terms down contractually, an agency supplement (DFARS, VAAR, …) may add requirements, and clauses listed below (if any) may order this clause into subcontracts from the outside.
Where it's prescribed
As prescribed in 11.703(b), insert the following clause:
Prescribing reference: FAR 11.703(b).
The official text, verbatim
As prescribed in 11.703(b), insert the following clause:
Delivery of Excess Quantities (Sept 1989)
The Contractor is responsible for the delivery of each item quantity within allowable variations, if any. If the Contractor delivers and the Government receives quantities of any item in excess of the quantity called for (after considering any allowable variation in quantity), such excess quantities will be treated as being delivered for the convenience of the Contractor. The Government may retain such excess quantities up to $250 in value without compensating the Contractor therefor, and the Contractor waives all right, title, or interests therein. Quantities in excess of $250 will, at the option of the Government, either be returned at the Contractor’s expense or retained and paid for by the Government at the contract unit price.
(End of clause)