• 98% satisfied customers
  • 72h delivery
  • 30 dni na zwrot
Adjustable reamer 16.5-18.25 NRZe - Artykuły Techniczne
search
  • Adjustable reamer 16.5-18.25 NRZe - Artykuły Techniczne
  • Adjustable reamer 16.5-18.25 NRZe - Artykuły Techniczne - nr. 2
Varel

Adjustable reamer 16.5-18.25 NRZe

Varel Varel
15026
€25.89 tax inc.

Net price: €21.05

Brak w magazynie
Brak w magazynie

Call and order: (44) 755-04-05

Description

Adjustable reamer 16.5-18.25 mm – adjustable reamer for 17 and 18 mm

Technical data – HSS blades, shank with square drive for a tap wrench

Technical data
Adjustment range16.5–18.25 mm
DesignationNRZe to PN
BladesHSS, in inclined grooves
Diameter adjustmenttwo nuts
Shank diameter10.5 mm
Shank square8.3 mm
Overall length173 mm
Blade length55 mm
Drivetap wrench
Adjustable reamer 16.5-18.25 mm NRZe – dimensional drawing, HSS blades, shank with square drive
Adjustable reamer 16.5-18.25 mm NRZe – dimensional drawing, HSS blades, shank with square drive

Adjustable reamer 16.5-18.25 mm The NRZe finishes holes from 16.5 to 18.25 mm, including the full 17 and 18 mm sizes. Set the diameter with two nuts that move the high-speed steel (HSS) blades along inclined grooves in the body. For a 18 mm hole, use a 17.75 mm drill bit; for a 17 mm hole, use a 16.75 mm drill bit. Remove the 0.25 mm allowance in two passes. Operate it by hand with a tap wrench fitted over the square on the shank.

Manufacturers design adjustable blade reamers for repair and assembly work. They are useful wherever a hole needs to be fitted to the part at hand. The diameter is then set to the size of the part, rather than to the standard size series of fixed reamers.

Which size to choose: 16.5-18.25 mm and adjacent sizes

The 15.5-17.5 mm reamer also covers holes from 16.5 to 17.5 mm. This reamer extends higher, to 18.25 mm, and has longer blades: 55 mm compared with 52.5 mm. From 18.25 mm, use the 18.25-19.75 mm reamer with a 9 mm square, which requires a No. 3 tap wrench.

How diameter adjustment works – blades and two nuts

NRZe reamer construction and measuring the diameter setting

The body has inclined grooves around its circumference, each holding an HSS blade. Two nuts, front and rear, retain the blades at both ends. Moving the blades along the grooves moves their cutting edges away from or toward the axis. This changes the cutting diameter over a range of 1.75 mm, from 16.5 to 18.25 mm. This is why the tool is also called an adjustable reamer.

NRZe adjustable reamer construction – blades in inclined grooves between the front and rear nuts
NRZe adjustable reamer construction – blades in inclined grooves between the front and rear nuts

Adjustment in three steps

First, loosen one nut. Then tighten the other — the blades will move to the new diameter. Finally, lock the blades by tightening the first nut. The rear nut, on the shank side, provides the main clamping force; the front nut is only snugged up. Tighten carefully. Excessive force bows the blades outward and causes the reamer to catch in the hole.

How to measure the set diameter

With an even number of blades, measure the diameter across two opposite blades using a micrometer. With an odd number, a groove lies opposite each blade, so the micrometer will read too low. In this case, use a setting ring or a hole of known diameter. Insert the reamer and expand the blades until they contact the hole wall.

How to ream step by step – tap wrench and clockwise rotation

Guidelines for using an adjustable hand reamer

Insert the reamer into the hole and apply light pressure so the blades engage the wall immediately. The tap wrench must fit the square closely to ensure smooth rotation without jerking. Align the reamer axis with the hole axis. For a longer hole, check the alignment with a square.

Hand reaming in six steps

1
Drill a hole
Use a 17.75 mm drill bit for a 18.0 mm hole. Remove the 0.25 mm allowance in two passes.
2
Set the diameter
Loosen one nut, move the blades with the other, then lock the first nut.
3
Fit the tap wrench
Fit it to the square and align the reamer with the hole axis.
4
Turn clockwise
Turn smoothly with light, even pressure.
5
Withdraw the reamer
Keep turning clockwise, including as the blades leave the hole.
✓
Check the hole
Too tight? Set a larger diameter and make a second pass.
Guidelines based on adjustable reamer manufacturers' instructions.
Hand reaming – adjustable reamer in a tap wrench, clockwise rotation
Hand reaming – adjustable reamer in a tap wrench, clockwise rotation

As the blades emerge from the far end of the hole, resistance drops suddenly. Reduce pressure at this point, but maintain the same turning speed. Otherwise, the reamer will jump through the end of the hole and leave it uneven.

▲
Never turn counterclockwise

Turning counterclockwise in the hole dulls the blades and may chip them. It can also loosen a nut and change the setting. Turn clockwise when withdrawing the tool as well; otherwise, you will scratch the hole wall.

How much material one pass removes

Reaming allowance and drill bit selection

This tool finishes a hole rather than drilling it. It removes a thin layer: from 0.05 to 0.15 mm on the diameter in one pass. A smaller allowance produces a smoother wall. Too little allowance is detrimental, as the blades rub against the wall instead of cutting and become dull faster.

Enlarged view of the reaming allowance – drilled hole and layer removed by the blades
Enlarged view of the reaming allowance – drilled hole and layer removed by the blades

Calculation: 18 mm hole after drilling with a 17.75 mm drill bit

Diametral allowance = finished hole diameter 18.0 mm − drill bit diameter 17.75 mm = 0.25 mm. This exceeds the 0.15 mm that the blades remove in one pass. Set the first pass to 17.9 mm – it will remove 0.15 mm. Set the second to 18.0 mm – it will remove the remaining 0.1 mm.

Finished hole [mm]Drill bit [mm]Diametral allowance [mm]Layer thickness at the wall [mm]Passes
17.016.750.250.1252: set to 16.9, then 17.0
17.517.250.250.1252: set to 17.4, then 17.5
18.017.750.250.1252: set to 17.9, then 18.0
18.2518.00.250.1252: set to 18.15, then 18.25

The first pass removes 0.15 mm, the maximum the blades can remove at once. The second, finishing pass removes the remaining 0.1 mm and smooths the bore surface. Each pass must remove at least 0.05 mm.

Tap wrench and lubrication – what to prepare

Tap wrench for a 8.3 mm square and oil suited to the material

Tap wrench No. 2

The shank square measures 8.3 mm. Select an adjustable tap wrench to DIN 1814, size No. 2. It accommodates squares from 3 to 9 mm and fits M4–M12 taps.

With oil or dry

Workpiece materialLubrication
Steel and cast steelcutting oil or emulsion
Aluminum alloyscutting oil or emulsion
Gray and malleable cast irondry
Bronze and brassdry

Remove chips from the reamer after use. Before adjusting the blades, also clean the body grooves so the blades move evenly.

Adjustable reamer 16.5-18.25 mm The NRZe covers the full 17 and 18 mm sizes. The reamer is 173 mm long, and its blades are 55 mm long. The drill bits offered in this range come in 0.25 mm increments, so ream the hole twice. For 18 mm, use a 17.75 mm drill bit and set the reamer to 17.9 and then 18.0 mm. The 8.3 mm square fits a No. 2 tap wrench.

Questions about drill bits, size selection, and operation

Frequently asked questions about hand reaming

With a 17.75 mm drill bit. It leaves a 0.25 mm allowance, so ream twice: to 17.9 and 18.0 mm. The first pass removes 0.15 mm, and the second removes 0.1 mm.

The 15.5-17.5 mm and 16.5-18.25 mm reamers cover a 17 mm hole. Prepare it with a 16.75 mm drill bit and ream twice, to 16.9 and 17.0 mm.

Clockwise, just as when reaming. Clockwise rotation protects the blades and the hole wall. It also keeps the nuts in place, so the setting does not change.

Yes, at very low speed and with plenty of oil. At high speed, the hole may end up larger than the setting. Using a tap wrench provides the best control.

Product accessories

Tap wrench No. 3

Reference: 085009 In stock > 10 items

€13.16

€16.18 brutto

Reviews

No customer reviews for the moment.

Add a review about the product

Adjustable reamer 16.5-18.25 NRZe

Adjustable reamer 16.5-18.25 NRZe

Shipping

All orders are delivered by courier company GLS. For orders exceeding 369 PLN gross shipping is FREE

Courier GLS Przelew24 / Prepayment 14,76 zł gross Delivery time 1 working day
Courier GLS Cash on delivery 17,26 zł gross Lead time 1 working day

This website uses its own and third-party cookies to improve our services and show you advertising related to your preferences by analyzing your browsing habits. To give your consent to its use, press the Accept button.

More information