Standard Products
Fine Boring Bars with Micro Bore Units
Fine Boring Bars with Micro Bore Units
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Facts & Advantages
  •   Precision Finish Boring Bar with high accuracy & repeatability.
  •   Used for machining close tolerances.
  •   Facilitates precision adjustment with least count of 1 micron (0.001mm) radially.
  •   Used for finish boring application with a range of diameters from 20mm to 168mm.
  •   Tailor made tools with similar concept also available on demand for the application of Back Boring, OD Turning & Undercut machining.
  •   Pre-loaded (pre-tensioned) assembly of MBU guaranteeing almost zero backlash.
  •   Adjustment can be done directly while the tool is on the machine, thus reducing downtime or setting time.
  •   Available in a wide range of variants and inserts enabling high degree of flexibility & a variety of precision boring applications.
  •   Apart from the standard product range, tailor made fine boring bars are also manufactured on demand.
Nomenclature Code Key for Ordering Fine Boring Bar with MBU
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Nomenclature Code Key for Ordering MBU
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Fine Boring Bar with MBU
include/img/Fine Boring Bars - MBU/Std Range for id boring/Std Range BT 40/Big 1.jpg
include/img/Fine Boring Bars - MBU/Std Range for id boring/Std Range BT 40/Big 2.jpg
include/img/Fine Boring Bars - MBU/Std Range for id boring/Std Range BT 40/Big 3.jpg
include/img/Fine Boring Bars - MBU/Std Range for id boring/Std Range BT 40/Big 4.jpg
include/img/Fine Boring Bars - MBU/Std Range for id boring/Std Range BT 40/Big 5.jpg
include/img/Fine Boring Bars - MBU/Std Range for id boring/Std Range BT 40/Big 6.jpg
Specification Chart
All dimensions are in mm.
Fig No. Sr. No. Item Code Spindle Taper MBU Item Code D (Ømin - Ømax) L GPL
Fig No.1
1 RTFBB 20-22 BT40 BT40 RTMBU ALC 04 20-22 60 92
2 RTFBB 22-24 BT40 BT40 22-24 60 92
3 RTFBB 24-26 BT40 BT40 24-26 60 92
Fig No.2
4 RTFBB 25.4-28 BT40 BT40 RTMBU ALT 06 / RTMBU ALC 06 25.4-28 80 112
5 RTFBB 28-31 BT40 BT40 28-31 80 112
6 RTFBB 31-34 BT40 BT40 31-34 100 122
7 RTFBB 33.1-38 BT40 BT40 RTMBU ALT 09 / RTMBU ALTP 09 33.1-38 100 122
8 RTFBB 38-43 BT40 BT40 38-43 100 122
9 RTFBB 42.6-51 BT40 BT40 RTMBU ALT 11 / RTMBU ALTP 11 / RTMBU ALC 09 42.6-51 100 122
10 RTFBB 51-59 BT40 BT40 51-59 100 132
Fig No.3
11 RTFBB 59-67 BT40 BT40 59-67 100 132
12 RTFBB 67-75 BT40 BT40 67-75 100 132
13 RTFBB 75-83 BT40 BT40 75-83 100 132
14 RTFBB 83-91 BT40 BT40 83-91 100 132
15 RTFBB 91-99 BT40 BT40 91-99 100 132
16 RTFBB 99-107 BT40 BT40 99-107 100 132
17 RTFBB 107-115 BT40 BT40 107-115 100 132
Fig No.4
18 RTFBB 115-124 BT40 BT40 115-124 100 132
19 RTFBB 124-132 BT40 BT40 124-132 100 132
Fig No.3
24 RTFBB 60.6-72 BT40 BT40 RTMBU ALT 16 / RTMBU ALTP 16 60.6-72 100 132
25 RTFBB 72-84 BT40 BT40 72-84 100 132
26 RTFBB 84-96 BT40 BT40 84-96 100 132
27 RTFBB 96-108 BT40 BT40 96-108 100 132
28 RTFBB 108-120 BT40 BT40 108-120 100 132
Fig No.4 29 RTFBB 120-132 BT40 BT40 120-132 100 132
Notes
  •   Fine Boring Tools do not include Micro Bore Units and inserts. Order for Micro Bore Units to be placed separately.
  •   Lead time of 1-2 weeks for all options.
  •   Customized fine boring bars for other spindle tapers / Side-Lock type can also be provided but will be made to order with lead time of 3-6 weeks.
  •   Customized fine boring bars for special diameter ranges can also be provided but will be made to order with lead time of 3-6 weeks.
  •   Diameter range "D" calculated considering 0.4mm insert nose radius.
  •   For additional cutting length requirement, customized fine boring bars with anti-vibration treatment can be tailor made with lead time of 3-6 weeks.
  •   Above standard variants are for Left hand cutting only and for ID boring application only. Other Fine Boring Tools for Right hand cutting & other applications such as OD Turning, Undercut Machining & Back Boring can be tailor made as per requirement. For all these applications, standard Micro Bore Units are available from Renuka Tools.
  •   Renuka Tools strongly recommend using these Fine Boring Tools for one particular diameter only. Too much of fiddling with adjustments, may result in permanent damage of the Micro Bore Unit and thus need to be used with precautions.
  •   Please refer to Renuka Tools' Micro Bore Unit's catalogue / webpage for details of Micro Bore Units used in above Fine Boring Tools. Click here for further details on Micro Bore Units
  •   Maximum recommended material removal of 0.5mm diametrically.
Fine Boring Bar with MBU
include/img/Fine Boring Bars - MBU/Std Range for id boring/Std Range BT 50/Big 1.jpg
include/img/Fine Boring Bars - MBU/Std Range for id boring/Std Range BT 50/Big 2.jpg
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include/img/Fine Boring Bars - MBU/Std Range for id boring/Std Range BT 50/Big 4.jpg
include/img/Fine Boring Bars - MBU/Std Range for id boring/Std Range BT 50/Big 5.jpg
include/img/Fine Boring Bars - MBU/Std Range for id boring/Std Range BT 50/Big 6.jpg
Specification Chart
All dimensions are in mm.
Fig No. Sr. No. Item Code Spindle Taper MBU Item Code D (Ømin - Ømax) L GPL
Fig No.1
1 RTFBB 20-22 BT50 BT50 RTMBU ALC 04 20-22 60 103
2 RTFBB 22-24 BT50 BT50 22-24 60 103
3 RTFBB 24-26 BT50 BT50 24-26 60 103
Fig No.2
4 RTFBB 25.4-28 BT50 BT50 RTMBU ALT 06 / RTMBU ALC 06 25.4-28 80 123
5 RTFBB 28-31 BT50 BT50 28-31 80 123
6 RTFBB 31-34 BT50 BT50 31-34 90 133
7 RTFBB 33.1-38 BT50 BT50 RTMBU ALT 09 / RTMBU ALTP 09 33.1-38 90 133
8 RTFBB 38-43 BT50 BT50 38-43 90 133
9 RTFBB 42.6-51 BT50 BT50 RTMBU ALT 11 / RTMBU ALTP 11 / RTMBU ALC 09 42.6-51 90 133
10 RTFBB 51-59 BT50 BT50 51-59 100 143
Fig No.3
11 RTFBB 59-67 BT50 BT50 59-67 100 143
12 RTFBB 67-75 BT50 BT50 67-75 100 143
13 RTFBB 75-83 BT50 BT50 75-83 100 143
14 RTFBB 83-91 BT50 BT50 83-91 100 143
15 RTFBB 91-99 BT50 BT50 91-99 100 143
16 RTFBB 99-107 BT50 BT50 99-107 100 143
17 RTFBB 107-115 BT50 BT50 107-115 100 143
Fig No.4
18 RTFBB 115-124 BT50 BT50 115-124 100 143
19 RTFBB 124-132 BT50 BT50 124-132 100 143
20 RTFBB 132-140 BT50 BT50 132-140 100 143
21 RTFBB 140-148 BT50 BT50 140-148 100 143
22 RTFBB 148-156 BT50 BT50 148-156 100 143
23 RTFBB 156-164 BT50 BT50 156-164 100 143
Fig No.3
24 RTFBB 60.6-72 BT50 BT50 RTMBU ALT 16 / RTMBU ALTP 16 60.6-72 100 143
25 RTFBB 72-84 BT50 BT50 72-84 100 143
26 RTFBB 84-96 BT50 BT50 84-96 100 143
27 RTFBB 96-108 BT50 BT50 96-108 100 143
28 RTFBB 108-120 BT50 BT50 108-120 100 143
Fig No.4
29 RTFBB 120-132 BT50 BT50 120-132 100 143
30 RTFBB 132-144 BT50 BT50 132-144 100 143
31 RTFBB 144-156 BT50 BT50 144-156 100 143
32 RTFBB 156-168 BT50 BT50 156-168 100 143
Notes
  •   Fine Boring Tools do not include Micro Bore Units and inserts. Order for Micro Bore Units to be placed separately.
  •   Lead time of 1-2 weeks for all options.
  •   Customized fine boring bars for other spindle tapers / Side-Lock type can also be provided but will be made to order with lead time of 3-6 weeks.
  •   Customized fine boring bars for special diameter ranges can also be provided but will be made to order with lead time of 3-6 weeks.
  •   Diameter range "D" calculated considering 0.4mm insert nose radius.
  •   For additional cutting length requirement, customized fine boring bars with anti-vibration treatment can be tailor made with lead time of 3-6 weeks.
  •   Above standard variants are for Left hand cutting only and for ID boring application only. Other Fine Boring Tools for Right hand cutting & other applications such as OD Turning, Undercut Machining & Back Boring can be tailor made as per requirement. For all these applications, standard Micro Bore Units are available from Renuka Tools.
  •   Renuka Tools strongly recommend using these Fine Boring Tools for one particular diameter only. Too much of fiddling with adjustments, may result in permanent damage of the Micro Bore Unit and thus need to be used with precautions.
  •   Please refer to Renuka Tools' Micro Bore Unit's catalogue / webpage for details of Micro Bore Units used in above Fine Boring Tools. Click here for further details on Micro Bore Units
  •   Maximum recommended material removal of 0.5mm diametrically.
Back Boring Tool
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Notes
  •   Minimum Diameter ØD = Ø22.0mm
  •   Fine Boring Tools for Back Boring application will be tailor made as per requirements.
  •   For Back Boring applications, standard Micro Bore Units are available from Renuka Tools. Click here to know more
  •   Lead time of 2-3 weeks.
ID Boring & Undercut Machining
include/img/Fine Boring Bars - MBU/ID Boring & Undercut/Big 1.jpg
include/img/Fine Boring Bars - MBU/ID Boring & Undercut/Big 2.jpg
Notes
  •   Minimum Diameter ØD = Ø37.1mm
  •   Fine Boring Tools for ID Boring & Undercut Machining application will be tailor made as per requirements.
  •   For ID Boring & Undercut Machining applications, standard Micro Bore Units are available from Renuka Tools. Click here to know more.
  •   Lead time of 2-3 weeks.
OD Turning & Undercut Machining
include/img/Fine Boring Bars - MBU/OD Turning & Undercut/Big 1.jpg
include/img/Fine Boring Bars - MBU/OD Turning & Undercut/Big 2.jpg
Notes
  •   Minimum Diameter ØD = Ø12.0mm
  •   Fine Boring Tools for OD Turning & Undercut Machining application will be tailor made as per requirements.
  •   For OD Turning & Undercut Machining applications, standard Micro Bore Units are available from Renuka Tools. Click here to know more.
  •   Lead time of 2-3 weeks.
Operating Instructions
  •   Mount the Micro Bore Unit properly in the finish boring tool supplied by Renuka Tools. This can be easily done by simply tightening the mounting screws in a proper manner (Pic1).In case the tool is of any other brand ensure that the manufacturer adheres to the mounting instructions provided by Renuka Tools. Else, it might result in non-efficient working or even tool failure.
include/img/Fine Boring Bars - MBU/Operating Instructions/Big 1.jpg
  •   Set the required diameter before clamping the tool onthe machine, ideally on a tool pre-setter, or else with the help of a precise dial indicator (Pic2). During this setting, ensure that any one scale marking on the MBU inner scale coincides exactly with the extreme end marking on the outer vernier scale. This will automatically match some other inner scale marking with the other extreme end of the outer vernier scale (Pic3). This will help the user to quickly adjust after initial trial of tool..
include/img/Fine Boring Bars - MBU/Operating Instructions/Big 2.jpg
  •   See if the desired results obtained by running the tool on the machine. In case of any deviation in the desired results, kindly use the spanner for adjustment. For increasing the diameter, rotate in clockwise direction and for decreasing, rotate in counter-clockwise direction. The least count of the inner MBU scale is 20microns on diameter (i.e. 10 microns radially). Now use the vernier scale for adjustment. If the diameter reading has to be increased, kindly match the adjacent marking (of left side) with the nearest vernier scale marking. This will result in increase of 2 microns on the diameter (i.e. 1 micron radially) (Pic 3.1 Zoomed). For reduction of diameter, follow the same procedure in the opposite direction (Pic 3.2 Zoomed).
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  •   Maximum diameter adjustment can be checked from the rear end of the spanner (Pic4). Do not exceed the maximum limit as it may cause permanent damage to the unit.
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Precautionary Measures
  •   Due to constraints in the assembly tolerances, it is recommended that units, if damaged, are returned to Renuka Tools for assessment/repair in a controlled environment. Commercials for repair can only be determined after detailed assessment of the damaged unit.
  •   Renuka Tools Micro Bore Unit cannot be adjusted beyond its range and the maximum range can be checked from the thickness of the end portion of the spanner provided along with the unit. Exceeding the range might result in permanent damage to the unit.
  •   Kindly change the mounting screws and insert screws ahead in time to avoid accidents.
  •   In case of any observed decrease in accuracy over the time of usage, kindly request Renuka Tools for servicing the unit.