
Yost Model 2503 Bench Vise, Clamp-on Style
Model 2503 Clamp-on Vise:
Made of Gray Iron
Two steel guide rods provide smooth screw action
Yoke style screw clamp for mounting to bench tops ½” – 1-7/8” thick
Replaceable / interchangeable hard plastic (nylon) jaws. Mounted on vise.
Replaceable / interchangeable hardened steel jaws
The vise shall consist of a body with integral front and back jaws (back body with anvil
feature), a sliding front jaw body, guide rods, vise screw, harden steel jaws, hard plastic
jaws, and a sliding screw handle with a stop on each end. The back jaw and body
combination shall extend down and under (a bench / shelf) in a yoke style. A clamping
screw will extend through the bottom of the yoke and the swivel button at the top end of
the screw. A clamping screw handle (“T”, or sliding bar type) shall be provided at the
bottom end of the screw.
2503 102503 2-1/2” 3” 2-1/2” 4
Nomenclature:
2503: Yost Bench Vise, Clamp-on Style: 2-1/2” jaw width, 3” Jaw
Opening, equipped with Replaceable Hard Plastic Jaws
2503-02-HSJ: Replaceable Hardened Steel Jaws (1 Pair included)

Yost Vises 2-1/2” Clamp-on Style Bench Vise,
Furnished with Hard Plastic Jaw Inserts and Hardened Steel Jaw Inserts
1. Vise, Bench, Clamp Model 2503:
Vise, Bench, Clamp shall be a stationary base clamp-style vise bench. Nominal
jaw width is 2-1/2 inches and nominal jaw opening is 3 inches. All unmachined
surfaces shall be given either one coat of enamel or lacquer. In no case shall
fillers be used. All castings shall be of uniform quality, free of blowholes, porosity,
hard spots, shrinkage defects, cracks, or other injurious defects.
Figure 1: Standard Order:
Yost Model 2503: Shown with hard plastic
jaws mounted to vise, (1) pair of hardened
steel jaws included with each order.
Figure 2:
Yost Model 2503: Shown with hard steel
jaws mounted to vise, (1) pair of hard plastic
(nylon) jaws included with each order.
2. The vise shall consist of a body with back jaw, front jaw, vise screw, screw
handle, and bench-clamping screw. The vise shall be provided with guide rods.
The body shall be of cast iron, ductile iron, malleable iron, steel casting, or steel
forgings.
3. The bench clamping screw shall be of a commercial steel screw stock with either
a knob wing “T” or sliding bar handle. The clamping screw shall be capable of
permitting the vise to be securely tightened to bench tops which vary in thickness
from ½ to 1-7/8 inch in thickness.
4. The front jaw, except for jaw facings where specified, shall be of cast iron, ductile
iron, malleable iron, steel casting, or steel forgings. When front jaws and sliding
members are furnished, the sliding member shall conform to the requirements of

item #9. The front jaw shall be integral or attached to the sliding member. The
face of the front jaw shall remain parallel to the face of the back jaw in any
position of travel.
5. The sliding member shall be round. It shall have a smooth machined or cold
rolled finish. The member shall slide in the body with smooth action without
binding at any point throughout the full range of travel. Backlash in either
direction shall not exceed a maximum of one turn of one revolution of the screw.
A collar or other means shall be provided to prevent the screw form coming out
of the sliding member.
6. The vise screw shall be of steel not less than 60,000 psi yield and 80,000 psi
tensile strength. One end of the screw shall have a steel or cast iron head of
adequate size which shall be an integral part of the screw, welded to the screw,
or otherwise securely attached in a permanent manner. The head shall be
provided with a hole to receive the screw handle. The screw shall engage the full
length of the threaded bearing of the body when the jaw is at the maximum
opening.
7. The nut an integral part of the body shall be of malleable iron, threaded to
engage the thread of the screw. It shall fit properly in the body so that it is in
alignment with the screw and there is no binding of the screw in the nut when the
jaws of the vise are opened.
8. The screw handle shall be a straight; round steel bar with means provided at end
to prevent complete disengagement and shall slide freely in the hole of the screw
head.
9. The jaw facings shall be of hard plastic (Nylon), tool steel or mild steel, milled, or
otherwise machined parallel with part of the face that is applied to the castings.
Replaceable hard plastic (Nylon) jaw facings and hard steel jaw facings are
supplied as smooth facings.
10. This tool shall be marked in a plain and permanent manner with the
manufacturer’s name or trademark of such known character that the source of
manufacture may be readily determined.
Figure 3: Yost Model 2503

11. Vise Insert, Hard Plastic Jaws: Jaw inserts shall be hard plastic (Nylon) that is
capable of withstanding reasonable pressure exerted on it without deforming.
Inserts must be able to fasten securely to the bench vise and be able to be
removed and remounted again for use.
Figure 4:
Yost Model 2503-02-PLJ:
Hard plastic (Nylon) jaws with
mounting hardware, (1) pair mounted
to vise with each 2503 shipment.
Figure 5:
Yost Model 2503-02-HSJ:
(1) pair of hard steel jaws with
mounting hardware, shipped
along with each 2503 shipment.