Before using any UNSCREW-UMS® remove as many screws as possible with a screwdriver and READ THESE INSTRUCTIONS COMPLETELY.

Fig. 1

Fig. 2

Fig. 3

Screw Sizes UNSCREW

Using UNSCREW-UMS® Broken Screw Extractors

a. Drill a deep pilot hole in the head and bore through the rest of the head with the same size UNSCREW-UMS® (Go to Steps B. and C.1.& 3.) or consider Step A.1.b. b. Completely remove the screw head with a drill. Go to Step A.2.c.

Fig. 1.B.

When the shank is exposed, select the

recommended* UNSCREW-UMS® from Column B in the Table to the right and go to Step B.4., if it is relevant; if not, go to Step C. Fig. 1.C. When dealing only with the threaded portion of the screw, select the recommended* UNSCREW-UMS® from Column C in the Table. Proceed to Step B.4., if it is relevant; if

c. If the head has really corroded away the UNSCREW-

-UMS®

Shank

Thread

Length

Outside

(Fig. 1B)

(Fig. 1C)

Available

Diameter

A. Assessing the problem: 1. The slot is too badly damaged to remove the screw:

Recommended * UNSCREW-UMS® for Common

not, go to Step C.

1/16"

--

#2

1"

3/32"

#2

1 3/8”

1/8”

#4

#4 #6**

5/32”

#6

#8**

2” & 2 1/2”

3/16”

#8

#10**

2” & 2 1/2”

7/32”

#10

#12**

2” & 3”

1/4”

#12,14

#14,16,18*

2” & 3 1/2”

* 5/16”

#14,16,18

2. The head broke off of the screw: a. About ¼” below the surface of the wood: let the screw hole guide your UNSCREW-UMS®. If the screw stub is more than 1” below the surface, use a long length UNSCREW-UMS® (see Table in column 3). Go to Step B.

UNSCREW-UMS® whose inside diameter is a little smaller than the diameter of the screw where it broke (for a break at the thread, ignore the thread, look at the solid core)*. Proceed to Step B.4., if it is relevant; if not, go to Step C. 4. If you have removed head of the screw, or, if the screw is flush or protrudes, select an UNSCREW-UMS® 1 or perhaps 2

b. Above the wood: go to Step A.2.c.2.

sizes larger in diameter than the one you selected to remove

c. Flush or nearly flush with the surrounding wood, due to

the screw. Go to Step C.

drilling the head off, cutting the screw off or being the location of the break, you have two options:

#16,18,20*

2” & 4”

*

UMS ® may be stable on the nub so you can skip the drilling altogether. Go to Step B. and C.1.& 4.

2”

C. Removing fasteners: !! WEAR EYE PROTECTION !!

1) Drill a hole in guide block and fasten it over the stub (Fig. 3). A block of clear plastic with sand paper glued to it

1. First Step:

works well and is fast. This hole will stabilize your UNSCREW-

variable speed drill, a two - speed cordless drill or a bit brace.

3/8”

#16,18,20

#20**

2” & 4”

7/16” --2” & 4” 1/2” --2” & 4” * Note: Your skill and familiarity with the UNSCREW-UMS® may influence your choice of sizes. If in doubt, choose a larger one and work down to smaller sizes, as you become more proficient.

** For hardened screws of this wire size, use an UNSCREW-UMS® which has a 1/16” larger O.D. than that shown.

Insert and tighten the UNSCREW-UMS® a 2. Beveling the stub (see Fig. 2 and Step B.4.):

UMS® as it starts. Cut down about 1/16” and remove the block.

The UNSCREW-UMS® may wobble when you start the drill.

To seat the beveler on the stub of the screw, run the drill

The UNSCREW-UMS® will be stable and you can tilt the drill to

Centering the slot on one jaw of the chuck usually minimizes

VERY SLOWLY (100 rpm) IN REVERSE (counter -

follow an angled screw. Go to Step B.

this wobble; if not, try putting the slot in a gap between two jaws

clockwise) and apply gentle pressure. As the UNSCREW-

2) Bevel the top 1/16” of the stub (Fig. 2) with an

and pick the position with the least wobble. The wobble will not

UMS® starts to cut, increase the pressure on the drill and add

UNSCREW-UMS® one or perhaps two sizes larger than the

affect the extraction process unless it is extreme. If so, contact

enough power to keep the speed constant. When the beveler

one you will use for removing the screw. The larger size will be

us for a replacement. Go to Step C.2.

has cut down 1/16”, it will have chamfered the stub sufficiently

stable on the stub. We prefer this method. Go to Step B.

UNSCREW-UMS® up to 1/4” diameter may be used in a bit brace. The technique is the same as for a drill, but the rpm’s

B. Choosing the right size UNSCREW-UMS®:

to firmly seat the UNSCREW-UMS® which will remove the screw. Go to Step D.

can be slower. In a bit brace is the screw is normally backed

3. Boring through the head with an UNSCREW-UMS®:

Most of the UNSCREW-UMS® come in two

out when the UNSCREW-UMS® has cut down only 1/16” to

Drill a deep pilot hole in the head of the screw with a drill the

lengths. The long ones should be used ONLY when the top of

1/8”. Thus, when it is imperative to remove as little wood as

same size as the UNSCREW-UMS® which you will be using to

the stub is more than 1” below the wood or when removing a

possible, this is the best method. Cordless drills work very well

remove the screw.

1. Length:

very long fastener (e.g., 4”+).

Switch to the UNSCREW-UMS®. While

because they are easier to run slowly than conventional drills.

running the drill VERY SLOWLY (100 rpm) IN REVERSE, cut

2. If you know the wire size of your screw, refer to Fig. 1, B &

Higher amperage drills are best and low gear is recommended.

through the head. The remains of the head will be a ring, which

C and the Table in column 3 to select the recommended*

Smaller ones may be good for only a few extractions before

may ride up the UNSCREW-UMS® - O.K. If the ring does not

UNSCREW-UMS®; if not, go to Step B.3.

their heat sensitive switches shut them off.

ride up, knock it off the UNSCREW-UMS®.

3. If you do not know the wire size of your screw, select an

D. Extracting the fastener:

Select as large an UNSCREW-UMS® as will fit in the core of

IT WILL BE HOT ! ! !

To remove all fasteners, run the drill or bit brace VERY

the fastener for maximum torque and strength. Drill the proper-

1. To remove an intact screw, secure a hardwood block in

SLOWLY (100 RPM) IN REVERSE (you should be able to

sized pilot hole in the fastener. Follow the normal procedure for

a vise, shift the drill into forward and screw the screw into the

see the slot as a blur) and apply moderate pressure. As the

extracting screws. Normally the UNSCREW-UMS® is ruined

block until it stops. Then, with the drill still running, pull back on

UNSCREW-UMS® starts to cut, add electricity when the drill

when it breaks the fastener free. Sometimes, however, the

the drill motor. The screw should stay in the block, but some

slows down too much and add pressure when it runs too fast.

UNSCREW-UMS® acts as a coring bit, leaving the threads in

screws will jam in the UNSCREW-UMS® and cannot be

You may also have to reduce the electricity at times, but only

the wood and you must drill out or tap the remaining metal.

removed.

when pressure doesn’t slow the drill quickly. The drill slows

We have used this method for removing small bronze

2. If the screw is weak and breaks into pieces during removal

sooner and more predictably with a pressure change than with

machine screws which were stuck in bronze. We do not

and for nails and machine screws, hold the UNSCREW-UMS®

an electrical one. (We have found that large fasteners, such

recommend this method for automotive or similar work.

firmly in a vise with the slot on one of the jaws. Drive the

as 3/8”+ lags and #24 screws, need more drill speed to

2. You may not be interested in the expansion aspect of the

protect the drill motor from overheating. At these speeds,

UNSCREW-UMS®, but may prefer simply to cut out a plug of

the slot will disappear.) Excessive drill speed overheats and

wood with the screw in it. This may be the only way to

de-tempers the UNSCREW-UMS® causing their early demise).

remove screws which have been glued in place.

fastener out with one or more dulled finish nails or the equivalent. 3. In our experience the useful life of an UNSCREW-UMS® has ranged from 3 UNSCREW-UMS® for 1 screw to 87 screws

Ultimately you may find that you are exerting substantial

3. Hardened screws: Use the method in E.2. or choose an

pressure to cut the metal and make the UNSCREW-UMS®

UNSCREW-UMS® large enough so that the teeth avoid contact

expand, but the pressure may also just be moderate. Whatever

with the hardened metal, but small enough so that the threads

4. The UNSCREW-UMS® can be re-sharpened with an extra

worked was right and the next one will probably be a little

will make it expand as it cuts (see the Table) Hardened screws

slim triangular file and the internal bevels can be reset with a

different.

come out easily as they must be slippery so that they can be

burr. When an UNSCREW-UMS® expands, it can be squeezed

driven in without breaking.

back into shape with pliers. Eventually this will cause the tool to

The shaft of the screw acts as a guide, so stay sensitive to it

for one UNSCREW-UMS®. Expect to average removing 5 to 8 screws per UNSCREW-UMS®.

to keep the UNSCREW-UMS® aligned properly. If the drill

4. Some screws spin freely in their holes and have no

crack, usually on the side opposite slot. The UNSCREW-UMS®

pushes back at you, release the pressure - the screw is backing

holding power, but they cannot be backed out with a screw-

should be discarded when twisted, bent, burned, permanently

out. A sudden change in the speed of the drill may indicate that

driver. We remove these screws with a modified hemostat or

expanded or cracked.

the screw threads have stripped in the wood, that a piece of the

needle-nosed pliers. Simply file the sides of the jaws until they

screw has broken off and is blocking the progress of the

will fit into the slot of the screw. You may want to notch the

UNSCREW-UMS® or that you are using insufficient pressure or

insides of the jaws so that they can get a better grip on the

Ideally, we would replace the broken screw with a new one

too much electrical power - check things out.

screw head. Slip the tool into the slot of the screw head and

of the same size. Often this is possible, but other times a larger

H. Replacing the Screw:

If the UNSCREW-UMS® loses the guiding stub, clear it and

open the jaws until you can push the points down into the

and/or longer screw is necessary, especially if the screw is

return it to the hole. Run the drill very slowly and feel the clicks.

countersink. Squeeze the handles together - the hemostat is

structurally important. You may want to try using epoxy resin to

That is the stub – point the UNSCREW-UMS® in that direction

nice because you can clip the handles together and lock onto

strengthen the wood in the hole. Be sure to use an epoxy

and it will reseat itself – a little messy, but it works.

the screw. With one or two twists, the screw will come out.

whose manufacturer recommends their product for this purpose

The depth to which an UNSCREW-UMS® cuts when removing sound screws can vary from 1/16” to the full length of

and be sure to follow their directions. Also, the hole may be F. Removing ring-shank and other nails:

the stub, but the norm is about 1/3 of the length of the stub.

1. Choose an UNSCREW-UMS® which fits snugly around

Badly corroded screws come out in ¼” pieces (see Step G,

the nail, just as you would for a screw. Drill a shallow pilot hole

Clearing the UNSCREW-UMS®).

or drill the head off the nail and follow the method for removing broken screws (Step C.2. or 3.). Pull back often to see if the nail

E. Alternative Ways to remove fasteners: 1. When you must not remove any of the material surrounding the fastener and when the fastener is large enough, a small UNSCREW-UMS™ can be run down entirely

is loose. 2. When a ring nail breaks free, spin it more to break up the surrounding wood fibers so that the nail can be removed. 3. Plan on replacing the nails with screws.

inside of the fastener. This technique can be very dangerous

4.Large ship’s nails can be removed by spot welding a stud

– YOU MUST HAVE A VERY FIRM GRIP ON THE DRILL -

onto the nail head. Then weld an extension to the stud and use

because just before the screw breaks free, the UNSCREW-

a slide hammer to gently tap out the nail.

UMS™ locks up in the fastener and the drill tries to rotate instead. If your grip is insufficient, the

G. Clearing the UNSCREW-UMS® and Reuse:

drill will probably hit your nose.

DO NOT TOUCH THE UNSCREW-UMS® --

plugged and perhaps redrilled.

We do this only in a non-

structural situation.

T & L TOOLS 24 Vinegar Hill Road Gales Ferry, CT 06335 Email [email protected] Website http://www.tltools.com

Tel 860-464-9485 Fax 860-464-9709