Tennsmith HBU48-16 Troubleshooting guide

OPERATION, PARTS & MAINTENANCE MANUAL
MODELS HBU48-16 HBS48-16
Proudly Made in the USA

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FOREWORD
This manual has been prepared for the owner and operators of Tennsmith HBU48-16 and
HBS48-16 model bench brakes. Its purpose, aside from operations instructions, is to
promote safety through the use of accepted operating procedures. Read all instructions
thoroughly before operating the brake.
Also contained in this manual is the parts list for your brake. It is recommended that only
Tennsmith or factory authorized parts be used as replacements.
WARRANTY
Your brake has a three year limited warranty from the date of purchase. The terms of the
warranty are stated on the warranty registration card shipped with your machine. Please
complete and return this card to activate your warranty.
SAFETY INSTRUCTIONS
1. Know the safety and operating instructions contained in this brochure. Become familiar
with and understand the limitations of this machine. Always practice safety.
2. Wear approved eye safety protection such ass glasses, goggles, etc., when operating
the brake to protect your eyes.
3. Wear protective foot wear or safety shoes.
4. Keep your hands clear of the nose bar and clamping area of the brake. Keep hands
clear of the apron area of the brake when making bends.
5. When bending capacity material use your legs and arms for making the bend, similar
to lifting a heavy object, to avoid back strain. Maximum length and capacity material is
a two person job. Adjust the counterweights to provide maximum assistance on heavy
bends.
6. Never use a pipe or bar on the clamp handles or apron handles for additional leverage.
7. Keep clear of the counterweight apron swing area while operating the brake.
8. Keep the work area around the brake clear and clean to avoid slipping or tripping.

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RECEIVING THE BRAKE
Upon receipt, closely examine the brake for damage during shipment. Report to your
distributor any damage that may have occurred during transit.
USE CAUTION IN HANDLING AND MOVING THIS BRAKE. Please note that brake is top
heavy. Lift the brake only from the ends as it is top heavy. Approximate weights for the
respective models are as follows:
HBU48-16 495lbs / 224.4 kgHBS48-16 460lbs / 208.7 kg
INSTALLING THE BRAKE
Locate the brake in a well lighted area on a solid workbench capable of supporting the 500
pound weight of the machine. The bench should be generally be secured to the floor by bolts
or lags screws. Be certain that you have adequate clearance to swing the apron and that the
brake is at a comfortable and convenient working height.
The brake should be removed for the skid. Use lag screws or bolts with expandable shields or
similar holding devices through mounting feet on the bottom of the lag assemblies to bolt the
brake to the bench. The brake must be fastened to the bench for safe operation.
THE BRAKE WILL NOT BEND PROPERLY IF IT IS NOT LEVEL.
ASSEMBLING THE BRAKE
The brake requires only minor assembly for proper operation. Place the counterweight in the
tube on the apron assembly’s left end so that the apron is balanced. Tighten the two set
screws in the tube to secure the counterweight in place. For working capacity material, the
apron handle extensions can be slipped on to the apron handles and secured in place by
tightening the set screws. Connect the stop rod to the apron assembly’s right end by slipping
the end of the rod through the hole in the bracket on the apron. Slip the cotter key through
the hole in the end of the rod and separate the legs of the key to keep it in place.
OPERATING THE BRAKE
CAPACITY: The capacity of the brake is 16 gauge mild steel or 20 gauge stainless. The
minimum recommended flange in capacity material with the apron support angle in place is
one inch. The capacity of the brake is reduced by four gauges when the apron support angle
is removed; i.e. 20 gauge mild steel or 24 gauge stainless. The capacity of the brake is
reduced by seven gauges when the apron insert is removed. By removing the apron support
angle and the apron insert, narrow reverse bends are possible in lighter gauge materials.
BENDING AND REPEAT BENDS: This function is accomplished by clamping the work piece
under the hold down assembly (902) so that the line of the bend is held at the forward edge
of the nose bar or fingers and by elevating the apron assembly (903) until the desired
degree of bend is obtained. The maximum degree of bend is approximately 140 degrees.
Due to the “spring back” in various materials some over bending maybe required to get the
desired bend angle. For repeat bends, adjust the stop on the stop rod to limit the swing of
the apron assembly. The stop is secured in place with a set screw.

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ADJUSTING FOR METAL THICKNESS: The hold down assembly (902) must be adjusted to
allow for clearance of the bend material according to the thickness of the material being
worked. This adjustment is made by slightly releasing the clamping pressure and moving the
forward edge of the nose bar or fingers back, away from the edge of the clamp block on the
base. This adjustment is made by loosening the bracket lock bolts (16) one on each
end of the base assembly and turning the adjustment bracket nuts (14) to move
the edge of the fingers / nose bar toward or away from the edge of the clamp
block. For 16 to 20 gauge and lighter material allow a clearance equal to twice the
thickness of the material being worked. A larger bend radius can be accomplished by
increasing the clearance.
ADJUSTING THE CLAMPING PRESURE: The clamping pressure should be adjusted
according to the thickness of the material being worked. A common cause of forming
problems is the result of either inadequate or excessive clamping pressure. Too much
clamping pressure on one or both handles typically will result in over bending the material on
that particular end or relative to the center portion of the brake. Not enough clamping
pressure force will allow the material to slip during the bending process and result in an
under bent section. This under bending is often encountered in the center of the brake.
Clamping pressure should be enough to hold the material securely in place but not so great
as to require undue effort in locking the clamp handles. Clamping pressure on the ends of
the brake is adjusted by turning the nuts (84) on the threaded rod portion of the yoke
assembly (907) which is below the clamp swivel (78). The lift of the hold down assembly is
adjusted by turning the nut above the clamp swivel. When the clamping pressure is properly
adjusted, lock the nuts against the clamp swivel to prevent any change in adjustment.
HBU48-16 BOX AND PAN BENDING: The fingers can be removed and repositioned on the
hold down assembly by moving the clamp handle fully to the rear and loosening the finger
clamp screws. Reposition the fingers to assemble the desired width and secure the fingers to
the hold down by tightening the finger clamp screws. Be certain that the tops of the fingers
are flush and parallel with the milled edge on the hold down and the finger clamps are
parallel with the bottom edge of the hold down. As a general rule, use the wider finger first
and fill in with the narrower fingers. Small gaps between the fingers may be left with no
adverse effect to the work piece. The maximum depth of box or pan which can be bent is 4-
Inches.
COUNTERWEIGHT ALIGNMENT: The counterweight on this brake can be adjusted to
balance the apron foe ease of operation. Loosen the set screws and raise or lower the
counterweight to achieve the desired degree of balance. Be certain to re-tighten the set
screws thus securing the counterweight in place.

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HEMMING:
Note: Forming hems is a secondary operation for a hand brake. If you adjust the
brake to close a hem in the center of the work piece, the brake most likely will not bend
straight. A hem is formed by making an acute (reverse) bend in the work piece and then
clamping the bent flange with the hold down (902) to press the flange closed (to 180
degrees). Often the hem will not fully close in the center of a long work piece due to fact that
the outer ends of the brake are more rigid than the center. Here it is especially important
that the brake is sufficiently crowned and that there is proper clamping pressure at the
center of the brake. Also the situation can be improved by inserting a strip of material (of the
same thickness as the work piece) between the work piece and the clamp block slightly
longer than the open portion of the hem. Re-clamp the hold down to close the hem. A
tinner’s mallet or hammer is also useful for closing hems. Be cautious not to use excessive
force on the clamp handles to close the hem.
ADJUSTING THE BRAKE
When your brake was assembled at the factory it was adjusted for proper operation. Due to
handling and repositioning, the brake my require adjustment and alignment. Read the
adjustment and operating instructions completely before making any adjustments. Operate
the brake and bend some material first before attempting any major adjustments.
BASIC ALIGNMENT: The clamp block on the base of the brake should be straight. This is
the reference point for all of the other alignment operations in adjusting the brake. Raise or
lower the center of the brake by adjusting the center of the brake by adjusting the center
truss rod. NOTE: Your brake has four truss rods which facilitate adjustment of the brake’s
three primary weldments. Adjustments are accomplished through rotation of the nut located
on the studs mounted perpendicular to the weldments.
HOLD DOWN ALIGNMENT: The forward edge of the fingers / nose bar on the hold down
assembly should be even and parallel to the edge of the clamp block on the base. Release
any clamping pressure on the hold down assembly by pushing the clamp handles slightly to
the rear. Loosen the set screw located on each end of the hold down assembly and turn the
eccentric to move the forward edge of the clamp block. Check to see that the edge of the
hold down is flush with the edge of the block throughout the entire length of the brake. The
central portion of the hold down assembly can be adjusted forward / backward and up or
down via truss rod adjustment.
OVERBENDING: The hold down assembly should be moved back on the end where the over
bending occurs by slightly unclamping the clamp handles, loosening the set screw and
turning the eccentric pin. When the correction is made retighten the set screw.

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PRECAUTIONS
DO NOT USE THE BRAKE TO BEND RODS, NAILS OR WIRE. THIS WILL CAUSE DAMAGE TO
THE EDGE OF THE NOSE BAR AND APRON.
ALWAYS ADJUST THE CLEARANCE AND CLAMPING PRESSURE FOR DIFFERENT
THICKNESSES OF MATERIAL.
DO NOT EXCEED THE CAPACITY OF THE BRAKE. MAKE CERTAIN THAT APRON SUPPORT
ANGLE AND APRON INSERT IS ATTACHED TO THE APRON ASSEMBLY WHEN MAKING
CAPACITY BENDS. OTHERWISE PERMANENT DAMAGE TO THE APRON MAY RESULT.
DO NOT bend seams, hems of locks unless the material is notched or the clearance is
adjusted to double the seam/hem thickness. The capacity of this brake is 16 gauge (0.063).
Multiple layers of material which exceed this dimension are beyond the capacity of the brake.
DO NOT USE PIPE EXTENSIONS TO GAIN ADDITIONAL LEVERAGE ON THE CLAMP HANDLES.
ALWAYS USE MATERIAL WITH SQUARE SHEARED EDGES FOR BEST RESULTS. ROLLED
EDGES, BENT OR WARPED MATERIAL WILL CUASE THE MATERIAL TO BOW WHEN BENT.
KEEP SHEAR BLADES AND SLITTER KNIVES SHARP.
ALWAYS BEND SHORT PIECES OF MATERIAL IN THE CENTER OF THE BRAKE IN ORDER TO
EQUALIZE THE STRESS.
ORDERING PARTS
When ordering parts please furnish both the model and serial number of your machine. Part’s
can be obtained directly from Tennsmith Inc.

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Bench Model Bending Brakes Specification
ModelsHBU48-16 HBS48-16
Capacity, mild steel 16ga / 1,6mm 16ga / 1,6mm
Capacity, bending
support angle removed 20ga / 1,0mm 20ga / 1,0mm
Bending length 48-1/4in / 1225mm 48-1/4in / 1225mm
Maximum depth of box 4 in / 101.7 N/A
Maximum lift of beam 1-1/4in / 31.75mm 1-3/4in / 44mm
Front to rear
adjustment 5/8in / 16mm 5/8in / 16mm
Minimum reverse bend 1/4in / 6mm 1/4in / 6mm
Minimum flange
in capacity material 1 in / 25 mm 1 in / 25 mm
Weight 495 lbs / 224.5 kg 460 lbs / 208.7 kg
Proudly Made in the USA