Phillips Oval Countersunk Head Machine Screws, Metric manufactured in Property Class 8.8 Steel (ISO 898-1 property class 8.8) are dimensioned to ISO 7047. The sections below give the mechanical and physical properties of the grade, its behavior in corrosive and elevated-temperature service, and the full size table.
Why Choose Property Class 8.8 Steel for Phillips Oval Countersunk Head Machine Screws, Metric
The workhorse medium-carbon alloy class for structural joints. For phillips oval countersunk head machine screws, metric, this matters when requires plating (zinc) for corrosion protection is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 898-1 property class 8.8 |
|---|---|
| Magnetic response | Magnetic |
| Service temperature | commonly limited to approx. +300 °C; confirm against the coating and the load |
| Corrosion characteristic | Requires plating (zinc) for corrosion protection |
Corrosion Behavior in Service
Carbon and alloy steel phillips oval countersunk head machine screws, metric require a coating for corrosion protection. Zinc plating (with or without passivation) is the most common; hot-dip galvanizing is used for outdoor structural service; black-oxide is mainly a tarnish-prevention finish for tool-room use.
Comparable Grades
For Phillips Oval Countersunk Head Machine Screws, Metric, class 10.9 or 12.9 is the comparable strength step. Move up when the joint preload approaches the proof load of the current class; move down when the joint is over-specified. For corrosion-critical service, switch to stainless A2 or A4.
Sizes of Phillips Oval Countersunk Head Machine Screws, Metric Available in Property Class 8.8 Steel
| Size | Pitch P (mm) | a (mm) | b (mm) | Head diameter dk (mm) | csh_diam (mm) | csh_height (mm) | n_min (mm) | r (mm) | t_mean (mm) | x (mm) | Length range l (mm) | Reference standard |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M1.6 | 0.35 | 0.7 | 25 | 3.6 | 2.8 | 1.0 | 0.46 | 0.2 | 0.4 | 0.9 | 3~16 | ISO 7047 |
| M2 | 0.4 | 0.8 | 25 | 4.4 | 3.6 | 1.2 | 0.56 | 0.3 | 0.5 | 1.0 | 3~20 | ISO 7047 |
| M2.5 | 0.45 | 0.9 | 25 | 5.5 | 4.5 | 1.5 | 0.66 | 0.3 | 0.6 | 1.1 | 3~25 | ISO 7047 |
| M3 | 0.5 | 1.0 | 25 | 6.3 | 5.3 | 1.65 | 0.86 | 0.4 | 0.7 | 1.25 | 4~30 | ISO 7047 |
| (M3.5) | 0.6 | 1.2 | 38 | 8.2 | 7.1 | 2.35 | 1.06 | 0.4 | 1.0 | 1.5 | 5~35 | ISO 7047 |
| M4 | 0.7 | 1.4 | 38 | 9.4 | 8.2 | 2.7 | 1.26 | 0.5 | 1.1 | 1.75 | 5~40 | ISO 7047 |
| M5 | 0.8 | 1.6 | 38 | 10.4 | 9.2 | 2.7 | 1.26 | 0.6 | 1.2 | 2.0 | 6~45 | ISO 7047 |
| M6 | 1.0 | 2.0 | 38 | 12.6 | 11.2 | 3.3 | 1.66 | 0.7 | 1.4 | 2.5 | 8~60 | ISO 7047 |
| M8 | 1.25 | 2.5 | 38 | 17.3 | 15.6 | 4.65 | 2.06 | 1.0 | 2.0 | 3.2 | 10~60 | ISO 7047 |
| M10 | 1.5 | 3.0 | 38 | 20.0 | 18.1 | 5.0 | 2.56 | 1.2 | 2.3 | 3.8 | 12~60 | ISO 7047 |
Dimensions are independent of the material: every size above is available in Property Class 8.8 Steel.
Custom manufacturing · Made to drawing
Need this screw in a grade that is not listed?
Grade 8 8 Steel is one of the grades the catalog describes. Material and finish are usually what drives a special — a grade the standard part is not stocked in, or a coating chosen against a salt-spray figure instead of a default. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
