SP50 / SP35 CRNO Coil | Semi-processed Non-oriented Silicon Steel Coil

Semi-processed state, customers can adjust magnetic properties through self-annealing
Flexible and cost-effective, suitable for customized motor design and small batch production
Good stamping formability, low work hardening rate during punching
Available in 0.5mm (SP50) and 0.35mm (SP35) common gauges
Supports subsequent slitting, flattening and other pre-processing services

Product Overview

SP50 and SP35 are semi-processed cold-rolled non-oriented silicon steel coils, which are semi-finished products without final annealing. The magnetic properties are not fully activated in the delivery state. Customers need to perform stress-relief annealing after stamping to eliminate stamping stress and achieve the target magnetic properties. This product is especially suitable for customers with independent annealing process and customized magnetic performance requirements.

SP50 corresponds to 0.50mm gauge and SP35 corresponds to 0.35mm gauge. The delivery state has good plasticity and low hardness, which is beneficial to the stamping process and reduces die wear. The product can be supplied with basic anti-rust coating, and the insulation coating can also be customized according to subsequent process requirements. The original mother coil width is 1000-1250mm, and precision slitting service from 5mm to 1240mm is available.

CRNO Coil

Chemical & Mechanical Property Snapshot

Grade	Si Content (%)	Iron Loss P₁.₅/₅₀ (W/kg)	Magnetic Induction B₅₀ (T)	Yield Strength (MPa)	Tensile Strength (MPa)	Elongation (%)
0.50 mm Series
50WW250	3.1–3.4	≤2.50	≥1.64	340	440	≥22
50WW310	3.0–3.3	≤3.10	≥1.65	330	430	≥23
50WW350	2.8–3.2	≤3.50	≥1.66	320	420	≥24
50WW400	2.7–3.1	≤4.00	≥1.67	310	410	≥24
50WW470	2.6–3.0	≤4.70	≥1.68	300	400	≥25
50WW600	2.4–2.8	≤6.00	≥1.69	280	380	≥26
50WW800	2.2–2.6	≤8.00	≥1.70	260	360	≥27
50WW1000	2.0–2.4	≤10.00	≥1.71	240	340	≥28
50WW1300	1.8–2.2	≤13.00	≥1.72	220	320	≥29
B50A250	3.1–3.4	≤2.50	≥1.64	340	440	≥22
B50A470	2.6–3.0	≤4.70	≥1.68	300	400	≥25
B50A600	2.4–2.8	≤6.00	≥1.69	280	380	≥26
B50A800	2.2–2.6	≤8.00	≥1.70	260	360	≥27
0.35 mm Series
35WW230	3.2–3.5	≤2.30	≥1.62	360	460	≥21
35WW250	3.1–3.4	≤2.50	≥1.63	350	450	≥21
35WW270	3.0–3.3	≤2.70	≥1.64	340	440	≥22
35WW300	2.9–3.2	≤3.00	≥1.65	330	430	≥22
35WW360	2.7–3.1	≤3.60	≥1.66	320	420	≥23
35WW400	2.6–3.0	≤4.00	≥1.67	310	410	≥23
B35A230	3.2–3.5	≤2.30	≥1.62	360	460	≥21
B35A300	2.9–3.2	≤3.00	≥1.65	330	430	≥22
B35A360	2.7–3.1	≤3.60	≥1.66	320	420	≥23
0.65 mm Series
65WW600	2.5–2.9	≤6.00	≥1.70	270	370	≥27
65WW800	2.3–2.7	≤8.00	≥1.71	250	350	≥28
Ultra-Thin High-Frequency Series
B20AHV800	3.3–3.6	≤8.00 (400 Hz)	≥1.55	410	520	≥15
B15AHV950	3.4–3.7	≤9.50 (400 Hz)	≥1.53	430	540	≥14
B10AHV900	3.5–3.8	≤9.00 (400 Hz)	≥1.50	450	560	≥12
ASTM Standard Grades
M250-50 / M19	3.1–3.4	≤2.50	≥1.64	340	440	≥22
M470-50 / M27	2.6–3.0	≤4.70	≥1.68	300	400	≥25
M600-50 / M36	2.4–2.8	≤6.00	≥1.69	280	380	≥26
M300-35	2.9–3.2	≤3.00	≥1.65	330	430	≥22
Semi-Processed Grades
SP50	1.8–2.3	Semi-processed (annealing required)	Semi-processed	230	330	≥28
SP35	2.8–3.3	Semi-processed (annealing required)	Semi-processed	330	430	≥22
Note: Semi-processed grades require customer-side stress-relief annealing to activate magnetic properties. HV series are tested at 400 Hz; all other grades are tested at 50 Hz / 1.5 T.

Detailed Technical Specifications

Item	Technical Specification
Product Name	SP50 / SP35 Semi-processed CRNO Coil
Full Name	Semi-processed Cold-Rolled Non-Oriented Silicon Steel Coil
Standard	GB/T 17951.2
Representative Grades	SP50, SP35
Nominal Thickness	0.50 mm (SP50) / 0.35 mm (SP35)
Mother Coil Width	1000–1250 mm
Slitting Width Range	5–1240 mm
Slitting Width Tolerance	±0.005 mm
Coil Inner Diameter	508 mm
Single Coil Weight	1.5–7 tons
Delivery State	Semi-processed, stress-relief annealing required by customer
Surface Coating	Basic anti-rust coating; custom insulation coating available
Processing Services	Slitting, flattening, laser cutting
Typical Applications	Custom motor design, prototype production, small batch motor manufacturing
MOQ	5 Ton for standard mother coil
Payment Terms	T/T, L/C at Sight
Packing	Waterproof kraft paper + galvanized steel strapping + seaworthy export wooden pallet
Trade Terms	FOB Qingdao, CFR, CIF, EXW optional
Delivery Time	7–15 working days after receiving deposit
Certificates	Mill Test Certificate (MTC); third-party inspection available upon request

Product Comparison Table

Semi-processed Grade	Thickness	Reference Full-process Grade after Annealing	Application Scenario
SP50	0.50mm	50WW470 / 50W470 / M470-50	General purpose small motors, household appliances
SP35	0.35mm	35WW300 / 35W300 / M300-35	Medium and small motors, high-speed motors

App Market

Reliable Steel Coil Solutions For Diverse Industrial Applications

Industrial Motor

Appliance Motor

Power Generation & Energy Storage Equipment

Product Packaging

Secure Export Packaging For Safe Handling And Delivery

FAQs

What is semi-processed CRNO silicon steel?

Semi-processed silicon steel is delivered without final annealing. Customers need to perform stress-relief annealing after stamping to obtain stable magnetic properties.

What is the difference between SP50 and SP35?

SP50 is 0.50mm thick for general motors; SP35 is 0.35mm thick for motors with higher efficiency requirements.

Do we need to anneal after stamping?

Yes, stress-relief annealing after stamping is required to eliminate processing stress and activate the magnetic properties of the material.

Can you provide insulation coating for semi-processed steel?

Basic anti-rust coating is provided by default. Customized insulation coating can be arranged according to your process requirements.

Can you provide annealing process recommendations?

Yes, we can provide recommended stress-relief annealing process parameters according to the grade and your production conditions.

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SP50 / SP35 CRNO Coil | Semi-processed Non-oriented Silicon Steel Coil