Rigibore

MBTR/SAB Units

Only used for finishing operations, this top adjusting unit is bush mounted, and is designed to fit both new and existing holes in bars or holders.

Bush units are offered in both 2 screw and 3 screw types to interchange with most other units of this type. The common feature of all bush units is that they are constructed of a bush plus a 'TR' unit.

Features:

  • Unique Design incorporating a precision ground collet
  • Split collet clamps to ACME type thread for accuracy and strength
  • Separate graduated dial seated on top face of hole
  • Rigidity maintained throughout full adjustment of unit
Benefits:

  • No deflection under load on eneven or intermittent cutting
  • Greater repeatability
  • Longer Insert Life
  • Most positive direct adjustment, high degree of rigidity, no dial slip when adjusting
  1. Insert the unit and roughly adjust as for type ‘R’.
  2. Using a hexagon wrench, tighten the retaining screw to fully compress the spring stack and back-off 12 turn max.
  3. Obtain final size by adjusting the dial only. Do not change the retaining screw setting.
    • When adjusting for a smaller diameter, always adjust under-size and then adjust clockwise to size.
    • ‘TR’ units are supplied with retaining screw and spring stack assembled in the correct order.
    • In the event that the spring stack becomes separated from the retaining screw and needs to be fitted, always remember that the disc spring nearest the unit should be with its outer rim towards the unit and other disc springs alternating as illustrated.
  4. This will ensure that the outer rim of the disc spring seats against the counterbore in the back of the boring bar (note: the number of disc springs varies with the unit size).

In extreme cutting conditions i.e. interrupted cuts etc. the action of the ‘TR’ unit can be made more rigid by re-stacking these disc springs, i.e. double stacking, but note that this will halve the adjustment range and must be pre-loaded by backing off the retaining screw only 14 turn (or less).

Additional disc springs may have to be purchased to achieve this. 'TR' units, as supplied are fitted with:

Unit Disc Springs
Size 2 6
Size 3 5
Size 5 3
Size 7 4
Size 10 4

For flexibility of use, the ‘TR’ unit can be used as for the standard ‘R’ unit, i.e. by fully tightening the retaining screw. In this way, the ‘TR’ unit becomes only marginally less rigid than the standard ‘R’ unit but will reduce the effective life of the disc springs that lose their spring characteristics after sustained full compression.

MBTR/SAB Bush Units - Angular Mounted - Size 1 Units
Approach Angle Min Bore Possible T
Top Adj
R
Total Radial Adj
H2
Min Height
K
Tool Point Offset
Insert Unit Code
mm inch mm inch mm inch mm inch mm inch
90° 24.00 .945 0.20 .008 2.00 .079 13.10 .516 1.35 .053 TC_ _ 06T1 (02) MBTR/SAB1-2B2
MBTR/SAB1-2B2-LH
75° 13.70 .539 -1.50 -.059 MBTR/SAB1-2B2L
MBTR/SAB1-2B2L-LH
45° 13.70 .539 -1.60 -.063 MBTR/SAB1-2B245
MBTR/SAB Bush Units - Angular Mounted - Size 2 Units
Approach Angle Min Bore Possible T
Top Adj
R
Total Radial Adj
H2
Min Height
K
Tool Point Offset
Insert Unit Code
mm inch mm inch mm inch mm inch mm inch
90° 30.00 1.181 0.28 .011 4.00 .157 16.50 0.650 1.32 .052 MBTR/SAB2-3B1 TC_ _ 06T1 (02)
MBTR/SAB2-3B1-LH
18.70 .736 0.80 .031 MBTR/SAB2-3B2 TC_ _ 0902 (04)
MBTR/SAB2-3B2-LH
16.35 .644 0.20 .031 MBTR/SAB2-3B2C CC_ _ 0602 (04)
MBTR/SAB2-3B2C-LH
75° 18.80 .740 1.10 .043 MBTR/SAB2-3B2L TC_ _ 0902 (04)
MBTR/SAB2-3B2L-LH
45° 19.75 .778 -1.60 -.063 MBTR/SAB2-3B245
MBTR/SAB Bush Units - Angular Mounted - Size 3 Units
Approach Angle Min Bore Possible T
Top Adj
R
Total Radial Adj
H2
Min Height
K
Tool Point Offset
Insert Unit Code
mm inch mm inch mm inch mm inch mm inch
90° 40.00 1.575 0.40 0.16 5.60 .220 22.80 .898 2.30 .091 TC_ _ 1102 (04) MBTR/SAB3-5B2M
MBTR/SAB3-5B2LH-M
21.75 .856 1.20 .047 CC_ _ 0602 (04) MBTR/SAB3-5B2CM
MBTR/SAB3-5B2CLH-M
75° 22.40 .882 1.30 .051 TC_ _ 1102 (04) MBTR/SAB3-5B2LM
MBTR/SAB3-5B2L-LHM
45° 22.85 .900 -1.60 -.063 MBTR/SAB3-5B245M
MBTR/SAB3-5B245-LH
16.30 .642 MBTR/SAB3-5B230M
MBTR/SAB Bush Units - Angular Mounted - Size 4 Units
Approach Angle Min Bore Possible T
Top Adj
R
Total Radial Adj
H2
Min Height
K
Tool Point Offset
Insert Unit Code
mm inch mm inch mm inch mm inch mm inch
90° 58.0 2.283 0.60 .024 8.00 .315 31.55 1.242 -.040 -.016 TC_ _ 16T3 (08) MBTR/SAB4-7B2
MBTR/SAB4-7B2-LH
32.57 1.282 1.60 .063 CC_ _ 09T3 (04) MBTR/SAB4-7B2C
MBTR/SAB4-7B2C-LH
75° 29.40 1.157 -3.20 -.126 TC_ _ 16T3 (08) MBTR/SAB4-7B2L
MBTR/SAB4-7B2L-LH
45° 31.50 1.240 MBTR/SAB4-7B245
MBTR/SAB Bush Units - Square Mounted - Size 1 Units
Approach Angle Min Bore Possible T
Top Adj
R
Total Radial Adj
H2
Min Height
K
Tool Point Offset
Insert Unit Code
mm inch mm inch mm inch mm inch mm inch
90° 25.0 .984 0.25 .010 2.50 .098 13.10 .516 2.00 .079 TC_ _06T1 (02) MBTR/SAB1-2B5
MBTR/SAB1-2B5-LH
7.50 .295 MBTR/SAB1-2F5S
75° 2.00 .079 MBTR/SAB1-2B5L
MBTR/SAB1-2B5L-LH
45° 13.70 .539 -0.80 -.031 MBTR/SAB1-2B545
13.20 .520 - - MBTR/SAB1-2B90
MBTR/SAB Bush Units - Square Mounted - Size 2 Units
Approach Angle Min Bore Possible T
Top Adj
R
Total Radial Adj
H2
Min Height
K
Tool Point Offset
Insert Unit Code
mm inch mm inch mm inch mm inch mm inch
90° 33.0 1.300 0.35 .014 5.00 .197 17.55 .691 3.00 .118 TC_ _0902 (04) MBTR/SAB2-3B5
MBTR/SAB2-.B5-LH
16.35 .644 4.00 .157 CC_ _ 0602 (04) MBTR/SAB2-3B5C
MBTR/SAB2-3B5C-LH
18.15 .715 9.40 .370 TC_ _0902 (04) MBTR/SAB2-3B5S
MBTR/SAB2-3B5S-LH
75° 17.55 .691 2.00 .079 MBTR/SAB2-3B5S
MBTR/SAB2-3B5L-LH
45° 19.75 .778 -0.80 -.031 MBTR/SAB2-3B545
- - MBTR/SAB2-3B90
MBTR/SAB Bush Units - Square Mounted - Size 3 Units
Approach Angle Min Bore Possible T
Top Adj
R
Total Radial Adj
H2
Min Height
K
Tool Point Offset
Insert Unit Code
mm inch mm inch mm inch mm inch mm inch
90° 45.0 1.770 0.50 .020 7.00 .276 21.95 .864 5.40 .213 TC_ _ 1102 (04) MBTR/SAB3-5B5M
MBTR/SAB3-5B5-LHM
21.75 CC_ _0602 (04) MBTR/SAB3-5B5CM
MBTR/SAB3-5B5C-LHM
21.95 .864 15.00 .591 TC_ _ 1102 (04) MBTR/SAB3-5F5SM
75° 3.20 .126 MBTR/SAB3-5B5LM
MBTR/SAB3-5B5L-LHM
45° -1.60 -.063 MBTR/SAB3-5B545M
21.85 .860 - - MBTR/SAB3-5B90M
MBTR/SAB Bush Units - Square Mounted - Size 4 Units
Approach Angle Min Bore Possible T
Top Adj
R
Total Radial Adj
H2
Min Height
K
Tool Point Offset
Insert Unit Code
mm inch mm inch mm inch mm inch mm inch
90° 63.0 2.480 0.75 .030 10.0 .394 31.50 1.240 8.35 .329 TC_ _ 16T3 (08) MBTR/SAB4-7B5
MBTR/SAB2-7B5-LH
31.40 1.236 6.35 .250 CC_ _ 09T3 (08) MBTR/SAB4-7B5C
75° 31.50 1.240 6.20 .244 MBTR/SAB4-7B5L
TC_ _ 16T3 (08) MBTR/SAB4-7B5L-LH
45° -1.60 -.630 MBTR/SAB4-7B545
29.00 1.142 - - MBTR/SAB4-7B90
Tool Insert Screw Retaining Screw & Wrench Kit Adjusting Wrench Torx Wrench Torx Driver
MBTR/SAB1-2B2 RS2045 BTR001/10/3 R26 R27 R27D
MBTR/SAB1-2B2LH
MBTR/SAB1-2B2L
MBTR/SAB1-2B245
MBTR/SAB2-3B1 BTR001/10/3 R36 R37 R37D
MBTR/SAB2-3B1-LH
MBTR/SAB2-3B2 RS2263
MBTR/SAB2-3B2-LH
MBTR/SAB2-3B2C RS2560
MBTR/SAB2-3B2C-LH
MBTR/SAB2-3B2L
MBTR/SAB2-3B2L-LH
MBTR/SAB2-3B245 RS2263
MBTR/SAB3-5B2M RS2560 BTR001/7/3
MBTR/SAB3-5B2LH-M
MBTR/SAB3-5B2CM
MBTR/SAB3-5B2CLH-M
MBTR/SAB3-5B2LM
MBTR/SAB3-5B2L-LHM
MBTR/SAB3-5B245M
MBTR/SAB3-5B245-LH
MBTR/SAB3-5B230M
MBTR/SAB4-7B2 RS4084 BTR001/8/3 R76 R77 R77D
MBTR/SAB4-7B2-LH
MBTR/SAB4-7B2C
MBTR/SAB4-7B2C-LH
MBTR/SAB4-7B2L
MBTR/SAB4-7B2L-LH
MBTR/SAB4-7B245
Tool Insert Screw Retaining Screw & Wrench Kit Adjusting Wrench Torx Wrench Torx Driver
MBTR/SAB1-2B5 RS2045 BTR001/10/3 R26 R27 R27D
MBTR/SAB1-2B5-LH
MBTR/SAB1-2B5L
MBTR/SAB1-2B5L-LH
MBTR/SAB1-2B545
MBTR/SAB1-2F5S
MBTR/SAB1-2B90
MBTR/SAB2-3B5 RS2263 BTR001/10/3 R36 R37 R37D
MBTR/SAB2-3B5-LH
MBTR/SAB2-3B5C RS2560
MBTR/SAB2-3B5C-LH
MBTR/SAB2-3B5S RS2263
MBTR/SAB2-3B5S-LH
MBTR/SAB2-3B5S
MBTR/SAB2-3B5L-LH
MBTR/SAB2-3B545
MBTR/SAB2-3B90
MBTR/SAB3-5B5M RS2560 BTR001/7/3 R36 R37 R37D
MBTR/SAB3-5B5-LHM
MBTR/SAB3-5B5CM
MBTR/SAB3-5B5C-LHM
MBTR/SAB3-5F5SM
MBTR/SAB3-5B5LM
MBTR/SAB3-5B5L-LHM
MBTR/SAB3-5B545M
MBTR/SAB3-5B90M
MBTR/SAB4-7B5 RS4084 BTR001/8/3 R76 R77 R77D
MBTR/SAB2-7B5-LH
MBTR/SAB4-7B5C
MBTR/SAB4-7B5L
MBTR/SAB4-7B5L-LH
MBTR/SAB4-7B545
MBTR/SAB4-7B90
Dimension Tolerance MBU1
MBTR/SAB1
MBU2
MBTR/SAB2
MBU3
MBTR/SAB3
MBU4
MBTR/SAB4
mm inch mm inch mm inch mm inch mm inch
A
+0.2
-0
+.008
-0
19.0 .7480 25.0 .9843 30.0 1.1811 46.0 1.8110
B H7
16.0 .6299 20.0 .7874 22.0 .8661 32.0 1.2598
b1 Drill point min 14.50 .571 18.50 .728 20.50 .807 30.50 1.200
C +0.2
-0
+.008
-0
12.50 .492 15.50 .610 24.00 .945 36.00 1.417
D +/-0.05 +/-.002 3.70 .146 4.00 .157 5.00 .197 6.30 .248
E 9.65 .380 12.5 .492 15.4 .606 23.0 .906
F
+0.1
-0
+.004
-0
4.6 .181 4.6 .181 6.5 .256 11.6 .457
G 2.5 .098 1.6 .063 1.8 .071 0 0
H
3.2 .126 3.2 .126 4.3 .169 5.4 .213
J M3X0.5 M3X0.5 M4X0.7 M5X0.8
K 10.0 .393 9.0 .354 13.0 .512 16.0 .630

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