Heavy duty construction of the No. 25 sharpener assures years of accuracy for edger saws, shingle saws and circular head saws.   It is the ideal machine for swaged tooth saws or blades tipped with high speed steel or cobalt.

The No. 25 Armstrong sharpener is engineered to accurately profile and sharpen a wide range of rip saws.  The heavy duty construction and 72" diameter capacity make it the ideal machine for solid tooth edger saws, circular head saws and shingle saws.

All adjustments are positive and easy to make.  Uniform feeding and accurate repeatability assure that the entire profile of every tooth is evenly and completely ground.  Oversized cams and heavy duty construction give the No. 25 Armstrong Sharpener the versatility to sharpen heavy shingle and log saws as well as the absolute uniformity and close tolerance required for thin gauge edger saws.

An adjustable feed arm is supplied as a standard feature on all new machines.  This makes it possible  to maintain a uniform tooth shape even though the saw is being ground down.  As illustrated in these tooth sketches, the back outline of the tooth remains the same as the saw is ground from 60" diameter down to 48".  Reducing the tooth space by as much as 30% is possible without altering the tooth shape or changing cams.

A conversion kit is available so that this unit can be easily installed in older No. 25 sharpeners.  No special tools are needed to make the change.

OTHER IMPORTANT FEATURES

Smooth Grinding
The rigid frame, heavy cast iron or steel components, ball bearing action and oversized cams make the action of the No. 25 sharpener grind so smooth that even 100 grit wheels can be used.  Just a light grinding can point up every tooth, so saws do not need to be swaged or retipped as frequently.

Uniform Tooth Outline
The entire profile of each tooth is precision ground.  The cams are engineered to provide special attention to the critical gullet area.  The descent of the grinding wheel is slowed as it approaches the bottom of the gullet and then, after a short pause to clean out case hardened material, it is gently eased up the back of the tooth.

Control of Gullet Shape
Unlike some so-called "profile sharpeners", the No. 25 Armstrong gives filers and saw doctors complete control over the gullet shape.  Simply by dressing the grinding wheel, a wide variety of chip breaker or frost notch gullets can be ground into the saw without changing cams.

Rocker Arm Action
Heavy cast iron rocker arms with replaceable steel shoes provide uniform action and heavy weight needed for smooth grinding.  There are no slides to wear, gibs to replace or bushings to foul.  The straight line action of the rocker arms keeps the grinding wheel centered over the saw.

Versatility
The No. 25 sharpener is the perfect sharpening machine for edger, shingle, head rig, lathe and bolter saws.  It is ideal for swaged and shaped, set, Cobalt Chromium Alloy or high speed steel tipped teeth.  Even carbide tipped saw plates can be gummed and new carbide seats ground when tips have been removed.  Attachments for small diameter saws or saws with extra long tooth spaces are available at extra charge.

Grinding Wheel Speed Control
A convenient hand wheel allows the operator to change the RPM of the grinding wheel to maintain the wheel rim speed to best match the composition and diameter of the grinding wheel.

Quick Cam Change
Wheel lift and feed action cams are supplied together as a matched set, timed and mounted on a quick change hub to produce one tooth outline.  A cam and hub assembly can be removed from the sharpener and replaced by another in less than one minute.

Economy
The smooth, precise action of the No. 25 sharpener allows the operator to point up the saw quickly, while removing less saw steel and wasting less grinding wheel.  These savings in saw steel, grinding wheels and time will soon pay back the initial cost of the sharpener.

Ball Bearing Saw Bushing
For an accurately jointed saw, smooth feeding, and long wear, a ball bearing saw bushing is supplied standard for any one size saw eye from 1 1/4" to 7 1/2" diameter.  Solid cones or bushings are available for other sizes in place of standard ball bearing cone at no extra charge.

Tooth shape produced by one pair of cams on a No. 25 Armstrong sharpener equipped with adjustable feed arm.  Note the back of the tooth remains the same as spacing becomes shorter.

Extra Long Tooth Space Option
Allows saw with tooth spaces up to 7" to be sharpened.  The standard machine will sharpen tooth spaces up to 4" with no modification required.  An inexpensive feed finger shoe, part No. 5077, can be easily installed in the standard machine to sharpen tooth spaces up to 4 3/4".

Safety Guards
To cover all exposed belts, pulleys and rotating arbors can be supplied factory installed on new machines or as a kit to be field installed on older No. 25 sharpeners.   While laws and regulations may vary in different locations, these guards meet all known North American requirements for operator protection in the above aspects, when properly installed.

Small Saw Attachment
Can be mounted on a standard machine to sharpen saws as small as 7" diameter.   This attachment can be quickly removed when larger saws are to be sharpened.

Carbide Inserted Saw Rest Pads
Available in place of standard or as replacement parts for extra-long wear on this part.  Order part No. 2908-C carbide inserted saw rest pad.