EN 1561 Standard Guide

Founding — Grey cast irons

Overview

KEY POINTS
What is Grey Cast Iron?	Cast iron with carbon present mainly as flake (lamellar) graphite
Application	Sand moulds or moulds with comparable thermal behaviour
Main Grades	5 grades by tensile strength + 6 grades by hardness
Key Feature	Properties depend on wall thickness (section sensitivity)
Graphite Form	Mainly Form I according to EN ISO 945-1
Material Designation	Based on 30mm diameter separately cast sample (most common)

MATERIAL CHARACTERIZATION OPTIONS
Option A	Tensile strength on separately cast or side-by-side cast samples
Option B	Tensile strength on cast-on samples
Option C	Tensile strength on samples cut from casting (add ‘C’ to designation)
Option D	Brinell hardness on casting
Option E	Combination of tensile strength and hardness (by agreement)

Figure 1 — Separately cast or side-by-side cast samples

Dimensions in millimetres

The thickness of the sand mould surrounding the samples shall be at least:
— 40 mm for types I and II;
— 80 mm for types III and IV.

Figure 2 — Cast-on sample: Type 1

Dimensions in millimetres

Figure 3 — Cast-on sample: Type 2

Dimensions in millimetres

Tensile Strength Grades

Material Grade	Material Number	Designation Basis	Typical Matrix	Typical Applications
EN-GJL-100	5.1100	30mm cast sample	Ferritic	High damping capacity, thermal conductivity
EN-GJL-150	5.1200	30mm cast sample, 10-20mm wall	Ferritic/Pearlitic	General engineering, low stress applications
EN-GJL-200	5.1300	30mm cast sample, 10-20mm wall	Ferritic/Pearlitic	Machine beds, housings, covers
EN-GJL-250	5.1301	30mm cast sample, 10-20mm wall	Pearlitic	Engine blocks, cylinders, brake discs
EN-GJL-300	5.1302	30mm cast sample, 10-20mm wall	Pearlitic	High strength applications, gears

IMPORTANT NOTE:

The designation is based on 30mm diameter separately cast sample (Type II)

Material grade designation uses wall thickness range 10-20mm

Maximum tensile strength = Minimum + 100 MPa

DETAILED TENSILE PROPERTIES

Material Grade	Material Number	Wall Thickness (mm) >	Wall Thickness (mm) ≤	Separately/Side-by-side Cast Sample Min Rm (MPa)	Separately/Side-by-side Cast Sample Max Rm (MPa)	Cast-on Sample Min Rm (MPa)
EN-GJL-100	5.1100	>5	≤40	≥100	≤200	—
EN-GJL-150	5.1200	>2.5	≤5	≥150	≤250	—
		>5	≤10	≥150	≤250	—
		>10	≤20	≥150	≤250	—
		>20	≤40			≥125
		>40	≤80			≥110
		>80	≤150			≥100
		>150	≤300			≥90
EN-GJL-200	5.1300	>2.5	≤5	≥200	≤300	—
		>5	≤10	≥200	≤300	—
		>10	≤20	≥200	≤300	—
		>20	≤40			≥170
		>40	≤80			≥155
		>80	≤150			≥140
		>150	≤300			≥130
EN-GJL-250	5.1301	>5	≤10	≥250	≤350	—
		>10	≤20	≥250	≤350	—
		>20	≤40			≥210
		>40	≤80			≥190
		>80	≤150			≥170
		>150	≤300			≥160
EN-GJL-300	5.1302	>10	≤20	≥300	≤400	—
		>20	≤40			≥250
		>40	≤80			≥225
		>80	≤150			≥210
		>150	≤300			≥190

NOTES:

• Values in BOLD are the designation basis (10-20mm wall thickness range)

• For wall thickness >300mm, values must be agreed between manufacturer and purchaser

• Cast-on samples have lower minimum values due to different cooling conditions

• See Figure 1 in standard for cast sample types and dimensions

BRINELL HARDNESS CLASSIFICATION

Material Grade	Material Number	Wall Thickness (mm) >	Wall Thickness (mm) ≤	Min HBW	Max HBW
EN-GJL-HB155	5.1101	>40	≤80	—	155
		>20	≤40	—	160
		>10	≤20	—	170
		>5	≤10	—	185
		>2.5	≤5	—	210
EN-GJL-HB175	5.1201	>40	≤80	100	175
		>20	≤40	110	185
		>10	≤20	125	205
		>5	≤10	140	225
		>2.5	≤5	170	260
EN-GJL-HB195	5.1304	>40	≤80	120	195
		>20	≤40	135	210
		>10	≤20	150	230
		>5	≤10	170	260
EN-GJL-HB215	5.1305	>40	≤80	145	215
		>20	≤40	160	235
		>10	≤20	180	255
		>5	≤10	200	275
EN-GJL-HB235	5.1306	>40	≤80	165	235
		>20	≤40	180	255
		>10	≤20	200	275
EN-GJL-HB255	5.1307	>40	≤80	185	255
		>20	≤40	200	275
		>10	≤20	215	290

IMPORTANT NOTES:

• Values in BOLD are the designation basis (40-80mm wall thickness range)

• Hardness DECREASES with INCREASING wall thickness

• For wall thickness >80mm, grades are NOT classified by hardness

• Minimum hardness range can be adjusted by agreement (minimum 40 HBW range)

• Use for machinability or wear resistance applications

• See Figure 4 in standard for Brinell knob details

Figure 4 — Example of a Brinell knob

Dimensions in millimetres

1: surface of casting

CAST SAMPLE TYPES AND SELECTION

Wall Thickness Range (mm)	Cast Sample Type	Sample Diameter (mm)	Test Piece Diameter (mm)	Figure Reference	Typical Use
≤10	Type I	15	10	Figure 1	Very thin walls
10-20	Type II	30	20	Figure 1	Standard designation
20-35	Type III	45	32	Figure 1	Medium walls
35-50	Type IV	75	32	Figure 1	Thick walls
50-100	30mm cast-on	30	20	Figures 2-3	By agreement
100-300	50mm cast-on	50	32	Figures 2-3	Very thick walls

KEY NOTES:

• Type II (30mm, highlighted in BOLD) is the MOST COMMON and used for material designation

• Sample must have comparable solidification as the casting relevant wall thickness

• For castings >1000kg and thickness >50mm, cast-on samples preferred

• Samples removed from mould at <500°C (unless otherwise agreed)

• See standard for detailed dimensions and requirements

SAMPLE TYPE DESCRIPTIONS
Separately Cast Sample	Cast in separate sand mould under representative conditions. Easy method for material designation. Represents single wall thickness only.
Side-by-Side Cast Sample	Cast in mould alongside casting with separate running system. Representative of concurrent castings.
Cast-on Sample	Attached directly to running system or casting. Better reflects casting properties but limited placement options.
Sample Cut from Casting	Cut from casting at critical location. Best reflects local properties but requires destruction. Add ‘C’ to designation (e.g., EN-GJL-250C).

MECHANICAL PROPERTIES

Based on 30mm as-cast diameter samples

Property	Symbol	Unit	EN-GJL-150	EN-GJL-200	EN-GJL-250	EN-GJL-300
Matrix Structure			Ferritic/Pearlitic	Ferritic/Pearlitic	Pearlitic	Pearlitic
Tensile Strength	Rm	MPa	150-250	200-300	250-350	300-400
0.1% Proof Strength	Rp0.1	MPa	98-165	130-195	165-228	195-260
Compression Strength		MPa	3.40×Rm	3.18×Rm	3.01×Rm	2.87×Rm
0.1% Compression Proof		MPa	195	260	325	390
Bending Strength		MPa	1.82×Rm	1.73×Rm	1.66×Rm	1.60×Rm
Shear Strength		MPa	170	230	290	345
Torsional Strength		MPa	1.36×Rm	1.36×Rm	1.36×Rm	1.36×Rm
Modulus of Elasticity	E	GPa	78-103	88-113	103-118	108-137
Poisson’s Number	ν	–	0.26	0.26	0.26	0.26
Bending Fatigue Strength		MPa	70-115	90-140	115-160	140-185
Bending Fatigue Strength		MPa	(0.46×Rm)	(0.46×Rm)	(0.46×Rm)	(0.46×Rm)
Fatigue Limit (Tension-Compression)		MPa	50-85	70-100	85-120	100-135
Fatigue Limit (Tension-Compression)		MPa	(0.34×Rm)	(0.34×Rm)	(0.34×Rm)	(0.34×Rm)
Torsional Fatigue Strength		MPa	55-95	75-115	95-135	115-150
Torsional Fatigue Strength		MPa	(0.38×Rm)	(0.38×Rm)	(0.38×Rm)	(0.38×Rm)

NOTES:

• Values are informative (not mandatory)

• Modulus of elasticity depends on graphite quantity/form and loading (non-linear curve)

• Fatigue values shown with factors in parentheses relative to tensile strength

• EN-GJL-100 omitted (used for special magnetic/machinability requirements)

PHYSICAL PROPERTIES

Based on 30mm as-cast diameter samples

Property	Symbol	Unit	EN-GJL-150	EN-GJL-200	EN-GJL-250	EN-GJL-300
Mass Density	ρ	kg/dm³	7.10	7.15	7.20	7.25

Property	Symbol	Unit	EN-GJL-150	EN-GJL-200	EN-GJL-250	EN-GJL-300
Specific Heat Capacity	c	J/(kg·K)
20-200°C			460	460	460	460
20-600°C			535	535	535	535

Property	Symbol	Unit	EN-GJL-150	EN-GJL-200	EN-GJL-250	EN-GJL-300
Linear Expansion Coefficient	α	µm/(m·K)
-100 to 20°C			10.0	10.0	10.0	10.0
20-200°C			11.7	11.7	11.7	11.7
20-400°C			13.0	13.0	13.0	13.0

Property	Symbol	Unit	EN-GJL-150	EN-GJL-200	EN-GJL-250	EN-GJL-300
Thermal Conductivity	λ	W/(m·K)
at 100°C			52.5	50.0	48.5	47.5
at 200°C			51.0	49.0	47.5	46.0
at 300°C			50.0	48.0	46.5	45.0
at 400°C			49.0	47.0	45.0	44.0
at 500°C			48.5	46.0	44.5	43.0

Property	Symbol	Unit	EN-GJL-150	EN-GJL-200	EN-GJL-250	EN-GJL-300
Resistivity	ρ	Ω·mm²/m	0.80	0.77	0.73	0.70

Property	Symbol	Unit	EN-GJL-150	EN-GJL-200	EN-GJL-250	EN-GJL-300
Coercivity	Ho	A/m	560-720	560-720	560-720	560-720
Maximum Permeability	µ	µH/m	220-330	220-330	220-330	220-330
Hysteresis Losses at B=1T		J/m³	2500-3000	2500-3000	2500-3000	2500-3000

NOTES:

• Values are informative (not mandatory)

• Thermal conductivity decreases with higher strength grades

• EN-GJL-100 has HIGHEST thermal conductivity and damping capacity

• Magnetic properties applicable to all grades shown

GUIDANCE VALUES FOR CASTINGS

IMPORTANT: These are ANTICIPATED values in actual castings (not for material designation)

Add ‘C’ to designation when using samples cut from casting (e.g., EN-GJL-250C)

Material Grade (with C)	Material Number	Wall Thickness (mm) >	Wall Thickness (mm) ≤	Min Rm (MPa) in Casting
EN-GJL-150C	5.1200	>2.5	≤5	165
		>5	≤10	150
		>10	≤20	135
		>20	≤40	115
		>40	≤80	100
		>80	≤150	90
		>150	≤300	—
EN-GJL-200C	5.1300	>5	≤10	200
		>10	≤20	180
		>20	≤40	155
		>40	≤80	135
		>80	≤150	120
		>150	≤300	—
EN-GJL-250C	5.1301	>5	≤10	250
		>10	≤20	225
		>20	≤40	195
		>40	≤80	175
		>80	≤150	160
		>150	≤300	155
EN-GJL-300C	5.1302	>10	≤20	270
		>20	≤40	235
		>40	≤80	210
		>80	≤150	195
		>150	≤300	185

CRITICAL NOTES:

• These values are GUIDANCE ONLY – not for material designation

• Values are LOWER than cast sample values due to actual casting conditions

• For non-uniform wall thickness castings, values are approximate

• Casting design should be based on measured tensile strength in critical parts

• For wall thickness >200mm, values must be agreed between manufacturer and purchaser

• Values vary due to section sensitivity and statistical effects

TEST METHODS AND REQUIREMENTS

Figure 5 — Tensile test piece

a: threaded
b: plain

TENSILE TEST
Standard	EN ISO 6892-1
Test Piece	See Figure 5 in standard (machined from cast sample)
Test Piece Types	Threaded or plain ends to suit clamping device
Temperature	Room temperature
Frequency	Minimum 1 sample per material grade (or per QA procedure)

TEST PIECE DIMENSIONS
Diameter d (mm)	Thread Type	Thread Length (mm)	Total Length Ls (mm)
6±0.1	M10	13	46
8±0.1	M12	16	53
10±0.1	M16	20	63
12.5±0.1	M20	24	73
16±0.1	M24	30	87
20±0.1	M30	36	102
25±0.1	M36	44	119
32±0.1	M45	55	143

BRINELL HARDNESS TEST
Standard	EN ISO 6506-1
Test Location	Agreed position on casting or Brinell knob (Figure 4)
Ball Diameter	Use largest possible compatible with section thickness
Purpose	Better accuracy and repeatability (integrates matrix and graphite)
Alternative Methods	Allowed if correlated with Brinell hardness

GRAPHITE STRUCTURE
Standard	EN ISO 945-1
Required Form	Mainly Form I (flake/lamellar graphite)
When Required	If agreed at time of order
Definition	More precise definition may be agreed upon

IMPORTANT NOTES:

• All samples must be adequately marked for full traceability

• If castings are heat-treated, samples must receive same heat treatment

• Alternative test procedures allowed by agreement

• See standard for detailed test piece drawings (Figure 5)

RETESTS AND QUALITY ASSURANCE

WHEN TEST IS NOT VALID

Invalid Test Reasons:

1. Faulty mounting of test piece or defective operation of test machine

2. Defective test piece due to incorrect pouring or machining

3. Casting defect in test piece evident after fracture

Action: Take new test piece from same cast sample or duplicate sample

NONCONFORMING TEST RESULTS
Initial Failure:	Manufacturer has option to conduct retests
Retest Requirement:	TWO retests for each failed test
Pass Criteria:	BOTH retests must meet requirements → Material conforms
Fail Criteria:	*One or both retests fail → Material does not conform*

HEAT TREATMENT
As-Cast Castings:	Heat treatment may be performed if properties not conforming
Heat-Treated Castings:	Re-heat treatment permitted if test results unsatisfactory
Sample Treatment:	Samples must receive SAME heat treatment as castings
Maximum Cycles:	Number of re-heat treatment cycles shall not exceed TWO (2)
Conformance:	If re-heat treated samples pass, castings are conforming

INSPECTION DOCUMENTATION
Standard:	EN 10204 – Types of inspection documents
When Required:	When requested by purchaser and agreed with manufacturer

KEY RELATIONSHIPS AND CORRELATIONS

HARDNESS TO TENSILE STRENGTH RELATIONSHIP
Formula:	HBW = RH × (A + B × Rm)
Where:	A = 100, B = 0.44, RH = Relative Hardness (0.8 to 1.2)
Note:	RH varies by raw materials, melting process, and metallurgical method
Important:	Difficult to give definitive limits for BOTH tensile and hardness due to RH variation
Foundry Practice:	Individual foundries can maintain RH nearly constant and indicate both hardness and tensile strength

WALL THICKNESS EFFECTS
Tensile Strength	DECREASES with INCREASING wall thickness
Hardness	DECREASES with INCREASING wall thickness
Reason	Different cooling velocities → different microstructure
Section Sensitivity	More pronounced in grey cast iron compared to other cast irons
Design Implication	Cast sample must match relevant wall thickness of casting

Example	Material Grade	Relevant Wall Thickness	Section Thickness	Expected Property	Property Type
Example 1	EN-GJL-300	40 mm	10 mm section	346 MPa	Tensile Strength
			40 mm section	270 MPa	Tensile Strength
			80 mm section	238 MPa	Tensile Strength
Example 2	EN-GJL-300	120 mm	80 mm section	250 MPa	Tensile Strength
			120 mm section	220 MPa	Tensile Strength
			200 mm section	212 MPa	Tensile Strength
Example 3	EN-GJL-HB195	40 mm	10 mm section	197 HBW	Brinell Hardness
			40 mm section	165 HBW	Brinell Hardness
			80 mm section	150 HBW	Brinell Hardness
Example 4	EN-GJL-HB195	120 mm	40 mm section	173 HBW	Brinell Hardness
			120 mm section	150 HBW	Brinell Hardness
			160 mm section	145 HBW	Brinell Hardness