TeresaMary...

There are no such things as a "Hi-Lok Reamers".

Any reputable reamer vendor can supply NAS897 reamers on demand.

Your engineers will have to review NAS897 and determine WHICH reamers are needed, based on the following minimum criteria:

1. reamer cutting diameter [take into account desired fastener "fit" in hole... interference or close-fit]
2.  Cutter-flute style [helical or straight]
3.  pilot diameter [if required]
4.  pilot length [if required]
5.  material type [HSS or Cobalt HSS]

NOTE: Reamers can effectively increase hole diameters 0.008--0.016" max in aluminum alloys per pass... or less in very hard alloys [CRES, Titanium, etc]. Any larger reaming increments may become "rough" or loose precision tolerances required for HL Instl. If holes have to be oversized beyond 0.017", I recommend adding intermediate reamers to "step-up" the holes.

NOTE: reamers can only produce a limited quantity of high quality holes before resharpening is required. Your engineers MUST help You estimate the quantity of each reamer required to accomplish the work, plus (1) or (2) for "aw-shit-I-dropped-it" [accidental damage] occurances.

NOTE: If reaming lots of holes in aluminum, or very hard materials, then Cobalt HSS may be a wise option [not the cheapest].

NOTE: Aerospace reamers are specified/made slightly different than industrial reamers. Differences are subtle, but important.

NOTE: The drill-motor and chuck are integral to a high quality reaming job. Insure that the drill-motor/chuck combinatiion is capable of solidly gripping/centering the largest bit [some reamer shanks are very large]; and that they are capable of spinning the [largest] reamer-bits "DEAD STEADY" [NO WOBBLE]... otherwise Your holes will be "junk" [way out of tolerance].

Regards, Wil Taylor

1st reply to your message is excellent. However; precision reamed holes in Aircraft parts also require some kind of fixturing or guide for the reaming. A portable guiding unit usually consists of a special "cup" with a removable guide bushing. Drill motor speeds have to be kept low and some kind of agent might have to be used to lubricate/cool the reamer, which should be frequently cleaned. These reamers have to be kept very sharp. A good check for a dull reamer is to slide your thumb along the edge of one of the flutes (Carefully) if it feels like its cutting YOU, or about to cut you, its in fairly good condition. If it feels smooth with no sharpness (Use a new reamer for comparison) it should be withdrawn from use. Most technicians will continue to use dull reamers, unless there are written instructions for quality assurance personnel to mandate involvement in the reamer checks. So make sure that if you have instructions, some kind of criteria for sharpness checks and stipulations that personnel not use the junk in their tool chests are also included. Also, as noted before, different types of interference fits need to be called out. These can be found in the Hilok manuals, or if your design or mod is Aircraft-type specific, you might want to call out the manufacturer's requirement for hole fit. Also remember that in some structural applications where cyclic fatigue plays a role, such as in main transverse floor beams, the quality of the holes has to be extremely high and will require a very specific inspection buyoff, AND will require a very specific type of Hilok fastener.