reaming - HSS

Think precision, Think HSS
REAMING
SUMMARY
1
REAMING TOOLS
2 Zoom on a reamer
REAMING PROCESS
11 The basics of reaming
3 Which HSS for maximum efficiency?
12 Hole quality and operating process
4 Coatings for the best performance
13 Speeds
5 Vocabulary
14 Feeds
6 Choose the right design
15 Cooling
7 Types of bevel leads
16 Wear
8 Number of teeth and hole quality
17 Problem solving
9 Dimensions and tolerances
10 Clamping reamers
REAMING
Bevel lead
Clamping
Coating
Tool material
Helix
Number of teeth
Dimensions
2
ZOOM ON A REAMER
TOOL MAKER’S TIP
Reach the highest
performance with
HSS-PM reamers
HSS
• Mainly for hand
reamers
HSS-E
HSS-E
HSS-PM
5% cobalt
8% cobalt
(powder
metallurgy)
• Basic choice
• For high
productivity
• High performance
• Long tool life
• For hard steels,
heat resistant
steels and titanium
alloys
• For soft steels,
cast iron and non
ferrous alloys
SUCCESS STORY
Manganese
steel
3
Operation
Solution
Cutting data
Benefits
• Reaming of a hole Ø 9.27 mm in an automotive connecting rod
• TiN coated HSS-PM 10.5% Co reamer
• vc 21 m/min, vf 245 mm/min, fz 0.068 mm
• Tool life x 3, i.e. 3000 holes
(vs. 1000 holes with a TiN coated carbide reamer)
WHICH HSS FOR MAXIMUM EFFICIENCY ?
TOOL MAKER’S TIP
For maximum
coating efficiency,
prefer a HSS-PM
substrate
TiN
TiAlN
or TiAL CN
Gold
MoS2
Grey-black
Black-violet
• Conventional, general
purpose coating
• High performance
coating
• Reduce friction and
avoid sticking
• For precision reaming in
most steel qualities, non
ferrous metals and
plastics
• For reaming of large
series in all materials
• For finish reaming of
difficult material such as
aluminium alloys and
titanium alloys
• Acts as a thermal barrier
SUCCESS STORY
Operation
Steel
sheets
4
Solution
Benefits
• Reaming of a hole Ø 8 mm, H7 in stay pipe composed of
4 hard-soldered and coated steel sheets
• TiN coated HSS 5% Co reamer with special geometry
• Tool life x 10, i.e. 2735 parts
(vs. 250 parts with a non-coated HSS reamer)
COATINGS FOR THE BEST PERFORMANCE
A REAMER AROUND
THE WORLD
Axis
Tang
French: un alésoir
German: eine
Reibahle
Shank
Land
Spanish: un
escariador
Secondary
clearance
Circular land
Overall
length
Radial face
Recess
length
Cutting edge
Body
Helix
angle
Cut
length
Bevel
lead
angle
Bevel lead
Diameter
VOCABULARY
Length
of bevel
lead
Clearance
Clearance
angle
Heel
Flute
5
Primary
clearance
Recess
Italian: un alesatore
Primary
clearance angle
Secondary
clearance
angle
Centre hole
6
Core drills
Front cutting reamer
Machine reamer
with straigth flutes
Machine reamer
with left helix
• To straighten a drilled
hole
• For lower precision holes
or before finish reaming
• For shallow holes
• Basic choice
• For good hole circularity
and quality
• Preferred for throughholes (the chip is pushed
in front of the tool)
Conical reamer
Expanding reamer
Expanding reamer
with indexable blades
Shell reamer
• For conical holes
• Adjustable diameter
• For lower precision holes
• Basic choice
• For large diameter holes
• Used in maintenance
workshops
CHOOSE THE RIGHT DESIGN
TOOL MAKER’S TIP
For improved hole
quality, use a low
angle chamfer
7
No bevel lead
(90° angle)
45° chamfer
Double chamfer
45° and 8°
8° chamfer
• For flat bottom holes
+ Improved hole
localisation
- Lower productivity (lower
feed)
- Lower surface quality
• Basic choice
• Universal use
• For through-holes
+ Improved surface finish
• For superfinishing
+ For high quality holes
TYPES OF BEVEL LEADS
TOOL MAKER’S TIP
For improved feed
and hole circularity,
select a higher
number of teeth
Circularity
with 2-tooth reamer
8
Circularity
with 4-tooth reamer
Circularity
with 6-tooth reamer
NUMBER OF TEETH AND HOLE QUALITY
Circularity
with 8-tooth reamer
TOOL MAKER’S TIP
The dimensions and
tolerances of a
reamer depend
on the dimensions
and tolerances
of the hole
d min = D max - 0.5 IT
d max = D min - 0.15 IT
Max. limit of hole size
Min. limit of hole size
d = reamer diameter
D = hole diameter
IT = hole tolerance
9
0.35 IT
0.15 IT
Min. limit of reamer hole size
Max. limit of reamer size
DIMENSIONS AND TOLERANCES
TOOL MAKER’S TIP
Use a floating holder
to compensate
alignment problems
between hole
and spindle
Morse taper shank
• Former basic choice
Plain shank
• The most popular shank
+ Available in long length for flexibility
and to compensate alignment defects
+ Available in short length for use on
highly accurate machines or with
floating holder
Angular correction
Radial displacement
Floating holder
10
CLAMPING REAMERS
Radial displacement
and angular correction
Square shank
• For hand reamers
• Reaming is a machining operation for enlarging and
finishing holes with accurate dimensions: the reamer
rotates with an axial displacement, and produces a
chip with constant thickness.
• In reaming, the workpiece is the principal support
during cutting.
• The hole quality depends on the bevel leads.
11
THE BASICS OF REAMING
TOOL MAKER’S TIP
= Circularity
IT = Hole tolerance
>0.1 MM
IT 8-9
>0.1 MM
IT <8
<0.1 MM
IT 8-9
<0.1 MM
IT 7
<0.1 MM
IT 6
Ra = Roughness
1. Conventional drill
+ 0.2, IT11
1. Conventional drill
+ 0.2, IT11
1. Spotting drill and
autocentering drill
+ 0.1, IT11
1. Spotting drill and
autocentering drill
+ 0.1, IT11
1. Spotting drill and
advanced
autocentering drill
+ 0.05, IT10
2. Core drill
IT8-9, Ra 3.2
or Reamer with
an helix
IT8, Ra 1.6
2. Core drill
IT8-9, Ra 3.2
2. Core drill
IT8-9, Ra 3.2
2. Core drill
IT8-9, Ra 3.2
2. Core drill
+ 0.025 IT8
3. Reamer with a
low helix angle
and 45° chamfer
IT7, Ra 1.6
3. Reamer with a
high helix angle
and double
chamfer
IT6, Ra 0.8
3. Reamer with a
low helix angle
and 45° chamfer
IT7, Ra 1.6
or Reamer with a
high helix angle
and double
chamfer
IT6, Ra 0.8
12
HOLE QUALITY AND OPERATING PROCESS
Uncoated HSS
reamer
Coated HSS
reamer
Copper alloys - short chips (Feed no. 6)
Aluminium Si <5% (Feed no. 6)
Aluminium Si 5-10% (Feed no. 6)
Cu Al Fe (Feed no. 6)
Cooper alloys - Long chips (Feed no. 6)
Aluminium Si > 10% (Feed no. 6)
Cu Al Ni (Feed no. 6)
Pure copper (Feed no. 6)
Magnesium (Feed no. 6)
Lamellar graphite cast iron (Feed no. 5)
Steels: 550 - 850 Mpa (Feed no. 5)
Plastics (Feed no. 8)
Steels < 550 Mpa (Feed no. 5)
Nodular graphite cast iron (Feed no. 4)
Thermosetting plastics (Feed no. 8)
Hardened cast iron > 270 HB (Feed no. 4)
Steels 850 - 1200 Mpa (Feed no. 4)
Pure nickel (Feed no. 1)
Austenitic stainless steels (Feed no. 3)
Pure Titanium (Feed no. 4)
Ferritic , martensitic , ferritic-austenitic stainless steels (Feed no. 3)
Titanium alloys (type TA6V) (Feed no. 4)
Duplex / highly alloyed stainless steels (Feed no. 3)
Nickel alloys < 850 Mpa (Feed no. 1)
Nickel alloys >850 Mpa (Feed no. 1)
0
10
20
30
40
Cutting speed in m/min
13
SPEEDS
14
Reamer Ø
mm
1
2
3
2.00
2.50
3.15
4.00
5.00
6.30
8.00
10.00
12.50
16.00
20.00
25.00
31.50
40.00
50.00
63.00
80.00
0.020
0.025
0.032
0.040
0.040
0.050
0.063
0.080
0.080
0.100
0.125
0.160
0.160
0.200
0.250
0.315
0.400
0.025
0.032
0.040
0.050
0.050
0.063
0.080
0.100
0.100
0.125
0.160
0.200
0.200
0.250
0.315
0.400
0.500
0.032
0.040
0.050
0.063
0.063
0.080
0.100
0.125
0.125
0.160
0.200
0.250
0.250
0.315
0.400
0.500
0.630
FEEDS
Feed column No.
5
6
F (mm/rev.)
0.040
0.050
0.063
0.050
0.063
0.080
0.063
0.080
0.100
0.080
0.100
0.125
0.080
0.100
0.125
0.100
0.125
0.160
0.125
0.160
0.200
0.160
0.200
0.250
0.160
0.200
0.250
0.200
0.250
0.315
0.250
0.315
0.400
0.315
0.400
0.500
0.315
0.400
0.500
0.400
0.500
0.630
0.500
0.630
0.800
0.630
0.800
1.000
0.800
1.000
1.250
4
7
8
9
0.080
0.100
0.125
0.160
0.160
0.200
0.250
0.315
0.315
0.400
0.500
0.630
0.630
0.800
1.000
1.250
1.600
0.100
0.125
0.160
0.200
0.200
0.250
0.315
0.400
0.400
0.500
0.630
0.800
0.800
1.000
1.250
1.600
1.600
0.125
0.160
0.160
0.200
0.250
0.315
0.315
0.400
0.500
0.630
0.630
0.800
1.000
1.250
1.250
1.600
2.000
TOOL MAKER’S TIP
Benefits of oil-hole reamers and high pressure
coolant
Prefer a high
performance
coalant to improve
hole quality and
avoid chip welding
• help prevent chip welding
• prevent damaging chemical reactions that occur at
high temperatures
• improve tool life
• allow an increase of cutting speeds
• improve surface finish
15
COOLING
TOOL MAKER’S TIP
Use a floating holder
to compensate
alignement problems
between hole and
spindle
Margin
New chamfer
Bevel lead
Rake
face
Small crater
Worn chamfer
Typical wear patterns of reamers include
• wear of chamfer on bevel lead
• small crater wear on the rake face
• wear of margins
16
WEAR
Problem
Causes
Solutions
Oversize hole
Alignment defect. Reamer not quite true
Correct alignment or use a floating holder
Tapering bore
Alignment defect
Correct alignment or use a floating holder
Too small hole
Worn reamer.
Reaming allowance too small
Recondition
Increase reaming allowance
Bore not true,
showing chatter marks
17
Concentricity and alignment problem
Use a floating holder
Poor surface finish
Reamer out of true. Inadequate machine data
Insufficient coolant
Check cylindrical trueness of edges and cutting
data. Increase coolant flow or use an oil-hole reamer
Scoring in bore
«feed marks»
Different teeth heights
Built-up edge
Check concentricity of bevel and circular land
Reduce cutting speed
PROBLEM SOLVING