Technical data on rails, pockets and cushions
According to the BCA rule book (with cloth covered rails)
6. Rail and Cushion
The rail width must be between 4 [10.16 cm] and 7 ½ inches [19.05 cm] including the rubber cushions. 18 sights (or 17 and a name plate) shall be attached flush on the rail cap with:
12 ½ inches [31.75 cm] from sight to sight on a 9-foot regulation table
11 ½ inches [29.20 cm] from sight to sight on a 8-foot regulation table. Note: this is for a 46x92 table. A 44x88 the measurement is 11"
The center of each sight should be located 3 11/16 (+ ) inches [93.6625 mm (+ 3.175 mm)] from the nose of the cushion. The sights may be round (between 7/16 [11.11 mm] and ½ inch [12.7 mm] in diameter) or diamond-shaped (between 1 x 7/16 [25.4 x 11.11 mm] and 1 ¼ x 5/8 inch [31.75 x 15.875 mm]). Any nameplates and score counters should be flush level with rail top. All rail bolts should be thus located that when properly torqued render a quiet and optimum rebound from any point of the cushion nose of the table.
7. Height of the Cushion
Rubber cushions should be triangular in shape with the width of the cloth-covered cushion being between 1 7/8 [4.76 cm] and 2 inches [5.40 cm] measured from the outer edge of the featherstrip to the nose of the cushion. Rail height (nose-line to table-bed) should be 63 ½% (+1 %) or between 62 ½% and 64 ½ % of the diameter of the ball.
8. Cushion Rubber
Table cushions should influence the speed of the table such that with placement of a ball on the head spot, shooting through the foot spot, using center ball english, with a level cue and firm stroke, the ball must travel a minimum of 4 to 4 ½ lengths of the table without jumping.
9. Pocket Openings and Measurements
Only rubber facings of minimum 1/16 [1.5875 mm] to maximum ¼ inch [6.35 mm] thick may be used at pocket jaws. The WPA-preferred maximum thickness for facings is 1/8 inch [3.175 mm]. The facings on both sides of the pockets must be of the same thickness. Facings must be of hard re-enforced rubber glued with strong bond to the cushion and the rail, and adequately fastened to the wood rail liner to prevent shifting. The rubber of the facings should be somewhat harder than that of the cushions.
The pocket openings for pool tables are measured between opposing cushion noses where the direction changes into the pocket (from pointed lip to pointed lip). This is called mouth.
Corner Pocket Mouth: between 4.5 [11.43 cm] and 4.625 inches [11.75 cm]
Side Pocket Mouth: between 5 [12.7 cm] and 5.125 inches [13.0175 cm]
*The mouth of the side pocket is traditionally ½ inch [1.27 cm] wider than
the mouth of the corner pocket.
Vertical Pocket Angle (Back Draft): 12 degrees minimum to 15 degrees maximum.
Horizontal Pocket Cut Angle: The angle must be the same on both sides of a pocket entrance. The cut angles of the rubber cushion and its wood backing (rail liner) for both sides of the corner pocket entrance must be 142 degrees (+1). The cut angles of the rubber cushion and its wood backing (rail liner) for both sides of the side pocket entrance must be 104 degrees (+1).
Shelf: The shelf is measured from the center of the imaginary line that goes from one side of the mouth to the other - where the nose of the cushion changes direction - to the vertical cut of the slate pocket cut. Shelf includes bevel.
Corner Pocket Shelf: between 1 [2.54 cm] and 2 ¼ inches [5.715 cm]
Side Pocket Shelf: between 0 and .375 inches [.9525 cm]